The Ni No Kuni film is an anime sequel to the game Ni no Kuni II: Revenant Kingdom. It was first released in Japan on 8 August, 2019, and on Netflix worldwide on 16 January, 2020.
High schooler Yu and his friend Haru get involved in a case involving his childhood friend Kotona, which forces them to go back and forth between another world that is different but is somewhat similar to their world, Ni no Kuni. The real world and Ni no Kuni, when Kotona's life is in danger, what's the ultimate choice the three of them have to make in Ni no Kuni?
On the roof of a hospital, an Old Man practices spell casting with his cane while standing on top of a radiator. He does this until nurse Miki implores him to stop. The spell the Old Man was trying to cast, was called Gateway, a spell that opens a doorway to an alternate world.
The scene skips to a high school gymnasium where star basketball player, Haru scores a basket. As he does this his wheelchair-bound friend, Yu watches from the sidelines and keeps track of the score and statistics behind the in-progress gameplay. Afterschool, Yu meets up with Haru and the two talk about the basketball game. The two of them are soon joined by Kotona, Haru's girlfriend and she joins the conversation. They all decide to go to a crepe shop that Kotona suggests, while unbeknownst to them they're tailed by a Black Hooded Man. Yu separates from the group once it's revealed the way to the Crepe shop is up a steep set of stairs. On his own, Yu returns home where he's greeted by his sister, Saki who is seen watering the flowers to the florist shop attached to their house. Immediately, Yu rides his wheelchair into his room and settles himself in his bed. In his bed, Yu reflects on his interactions with Kotona and then also with Haru. He then realizes the frustration he feels is mainly due to his jealousy of Haru and Kotona's relationship.
Meanwhile, Haru and Kotona are walking home together after coming from the Crepe shop. As they walk, Kotona notes that she feels bad for taking a route that made them exclude Yu. Haru then chimes in and suggests they take him along next time. The two then separate from each other and as Kotona walks home down a back alley, she's tailed by the Black Hooded Man. Fearful of her life, Kotona contacts Yu and begs him for help since Haru wouldn't answer his phone. Enlisting help from his Sister Saki, Yu is driven to Kotona's location, while Haru does a bit of shopping for Kotona's birthday. En route to Kotona's location, Yu tries to contact Haru, but to no avail and then fills Saki in of the situation. At Yu's request, he's dropped off at a book store and he asks Saki to continue trying to contact Haru. Tracing Kotona's steps, Yu finds Kotona struggling against the Black Hooded Man, who stabs her in her abdomen. Yu manages to break Kotona's fall as the Black Hooded Man escapes. It's at that moment that Haru arrives at the scene and in an agitated state, takes Kotona away from Yu and declares he'll take her to a hospital. Haru then takes the unconscious Kotona away from the scene and is soon chased after by Yu. They enter a busy street and Yu saves Haru and Kotona out of the way of a truck sacrificing his wheelchair in the process. Now stuck in between the street with fast-moving cars parallel to them, both Yu and Haru are transported to an alternate world.
Now in the city center of a completely different place. The two are astounded of not only their surroundings, but the outfits they're now wearing. Immediately they then realize that Kotona is gone. Figuring they can contact her with their cell phones, they learn that it was replaced with compasses. Once the two starts attracting attention from the town's people while sitting on the ground. So Yu then suggests they move; he then gets up and starts walking away. Haru calls Yu on out on this and the two become both astonished and then elated on the fact. As the two walks down the streets of the town, they both speculate where they are and what kind of town they're in. Ultimately, Yu theorizes they're in another world. Believing that Kotona might also be somewhere in that world and is healed due to Yu being able to use his legs, the two decide to find her.
They first start in a pub and immediately run into a Dogfolk person named Bauer Linden. The three of them sit at a table and Bauer without their consent brags a bit about a heroic tale of his. Yu cuts in mid-story and asks him if he's heard of a woman named Kotona. Instantly, Bauer agrees to help them find Kotona and they're soon joined by two other pub patrons. The barkeep lady chimes in after hearing Kotona's age is the same as Princess Astrid and directs the boys' attention to a poster of Astrid. Astonished the two claims that its Kotona. After learning of Astrid's location, Yu and Haru quickly head to the castle, but are stopped by the castle guards stationed by the gate.
Inside the castle, Knight-Captain Bertha visits the princess Astrid's room. In the room, King Fidelius, Chancellor Gnauss, Army leader Barton, and the princess' fairy caretaker Danpa all stay by Astrid's bedside. Bertha is briefed on Astrid's condition by Barton. The King then notes how even the healers of the kingdom cannot dispel a curse laid on the unconscious and bedridden princess. Gnauss reassures the king that a master in dispelling curses than those of Master Zeelock's Order who will soon arrive. Back outside the castle gates, Haru and Yu manage to infiltrate into the castle by hiding in a luggage wagon of Master Zeelock's Order. When the wagon stops in front of the castle doors, Haru and Yu each hide in a couple of vases and are carried inside the castle.
Once inside the castle, the two boys quickly get out of the vases and secretly watch the Master Zeelock's Order perform the curse exorcism. It, however, fails and kills the people of Master Zeelock's Order. Shocked by this event, the king is escorted out of Astrid's room, leaving both Yu and Haru alone in there. The two then check on Astrid's and when they do, the translucent dagger that appeared from the princess' chest after the failed ritual, fully manifests. Yu then grabs the dagger and tries to draw it from Astrid's chest. At that moment, Bertha barges into the room and demands answers to what they're doing. However, it's then that Yu manages to fully draw the sword out of Astrid's chest healing her.
Afterward, Yu and Haru are interrogated by Barton in the throne room. This continues until a languid Astrid arrives being escorted by Bertha and her two fairy servants and then greets her elated father. Bertha also corroborates the deed done by the two boys and Gnauss proposes to King Fidelius, the two be rewarded for their efforts. Fidelius agrees with the proposal and that evening the boys are escorted by to town by Bertha and her soldiers. Back at the pub, the boys are treated to dinner by Bauer and his two friends. They then discuss how princess Astrid wasn't Kotona and other things that seem to correlate with Astrid and Kotona. Haru though brushes the whole situation they're in as a dream and makes the best of it by having fun with the pole dancer. The barkeep lady then approaches Yu and allows the two to stay the night in the storeroom on the floor above the pub. When Yu leaves the pub and heads to the storeroom; instead of heading to bed, he heads back to the castle. He's accompanied by a little pink dog creature that has been following the two since they arrived in the new world. On the castle compounds, Yu heads to Princess Astrid's room.
At Princess Astrid's room, Yu witnesses Astrid in an argument with her servant Danpa. Once Yu is spotted, he tries to run away, but is stopped by Astrid. The two then go for a stroll while talking with each other. They soon reach an airship that is ridden to a place known as the Lake of Purity. There, she'll be able to expel any remaining impurities related to the curse from her body. Once they arrive there, Astrid prepares herself. When she's dressed appropriately for the ritual, Astrid walks into the lake until the water nearly reaches her shoulders and performs the ritual dance. The dance allows her to walk on the lake water as the lake lights up with a shimmering presence. The ritual dance is a success and once Danpa goes to fetch some herbs, Yu and Astrid have a heart to heart with each other. They talk about Kotona, the world Yu and Haru are from, and about Kotona lamentations. After this, the two jump in the lake and have fun with each other.
Back at the castle, Gnauss discusses matters involving Yu and Haru with King Fidelius. Gnauss believes the two are associated with a group known as the Black Banner. The following day, Yu awakens on the bed in the storeroom and is greeted by Haru. Immediately, an envoy from the castle relays a message from the king about inviting them to a swordplay exhibition. Soon, they're lead to a fully packed coliseum with King Fidelius, Barton, and Gnauss in attendance. Gnauss announces that the king wants to gauge their swordplay capabilities by having them face off against a group of swordsmen in a mock battle. As the two are encircled by their opponents, Princess Astrid arrives with Bertha and her soldiers. Astrid denounces the disrespect being shown to the heroes, but Gnauss claims that they're just fighting in a mock battle. The princess, however, still is against it, as Yu and Haru continue to struggles against their opponents. It was after Yu saves Haru when he was in a pinch, the two overwhelm their opponents and win the mock battle. This gains the two an audience with the king and his subjects. Once they reach them they're restrained under the accusation of being conspirators with the Black Banner. Figuring their only way out of the situation is returning to their original world, to which, the trigger is a being in a near-death experience. Haru and Yu jump toward the flame behind the king and are transported back to their world. From this scene, Gnauss deduces the two are "Wayfarers".
Finally, back in their own world, Kotona greets the two and an emotional Haru embraces her. They learn from her that a drowsy truck driver caused an accident that caused a bus to crash and killed several people in the process. The people that were killed, looked strangely like the men that performed the failed curse lifting ritual. A flashback involving Yu when he was 5 years old is shown where he talks with the old man at the hospital about another world and the rules that it's bound to. The following day, Yu relays this to Haru who sounds skeptical and continues to brush it off as a dream. Even so, Yu believes the entire experience was real and when they saved Princess Astrid, they, in turn, saved Kotona. However, Haru continues to brush off the situation to focus on the, "here and now".
Later that day Yu visits the hospital where he once met the old man, to see him again. The nurse there informs him that he's disappeared, but Yu believes he's in the otherworld. The next day at school, Haru and Yu learn that Kotona will be absent from school due to health reasons. Afterschool, Kotona reveals that she has a malignant tumor and has 3 months to live. Once Kotona leaves the two to return to the hospital she's staying at. Yu proposes Haru and he, return to the other world to save Princess Astrid again so that Kotona's fate will be changed. Haru, however, believes contrary to what they accomplished and goes on an abrasive tirade towards Yu. As this goes on, the Black Hooded Man arrives at the scene and transports the two to the otherworld. Haru ends up in a dark and dismal wasteland where a ruined castle is at. Inside the castle are triceratops-like monsters and soon Haru is met by a man known as Galeroth. On the other hand, Yu ends up back in the royal castle throne room and is restrained by Barton. Yu tries to reason with the king and Gnauss about Princess Astrid's well being is in danger, because his friend from another world Kotona is in danger again. Back to Haru who listens to Galeroth inform him about how the number of people in that world is predetermined. Furthermore, if one life that was destined to die in that world is spared the corresponding life in another will die. Returning back to Yu who continues to beseech the king and his court about how Astrid's life is still in danger. Bertha then arrives and warns that the Black Banner army is making a move. Also, Haru is a part of the uprising as well. This is proven true as now Haru, dressed in Black Banner clad armor and planning to kill Princess Astrid. Back to Yu, who denies that his tormented friend is really part of the Black Banner group, is given a chance by Gnauss. To prove himself, he must join the frontlines of the battle as the princess' guardian and kill Haru. King Fidelius allows this and thus Yu is conscripted into the battle.
Now dressed in a suit of armor, Yu is approached by Astrid. She requests that Yu kill with a magical dagger that her mother forged herself, to relieve Yu of any regret he has. Yu though refuses to do so and is obstinate towards Astrid's continued plea and thanks to Danpa joining in on the conversation is resolved to save them all.
Like a swarm, the Black Banner army arrives in Evermore's lands and start their invasion. With the war started the Evermore army starts to fight back. Haru and Galeroth arrive in the town square and Haru heads toward the castle. Meanwhile, upon seeing Haru's arrival at the castle, Yu goes to confront his former friend. The king is informed by Danpa of the dire situation, but is reassured that all is well from Gnauss. As the battle rages on in the town, Haru notices that his power has been greatly amplified due to the Black Banner Armor that he wears. Meanwhile, Astrid approaches her father and Gnauss to suggest they use the Mornstar. The weapon, however, was lost in the previous war and the one in the vault is a fake to maintain political power over the surrounding kingdoms.
Elsewhere, as Yu fends off the invading enemies, Haru arrives with the Black Banner army. Once they reach the castle gates, they're met by Bertha and her soldiers. Haru easily beats Bertha but is then confronted by Yu who tries to dissuade Haru from his goal. He, however, remains adamant in killing Astrid and the two fight. During the fight, a flashback involving the two when they were friends is shown where Yu saves Haru from a mean dog and the two then become friends.
Yu awakens back in his world and sees on a news broadcast that a fire has broken out in the Grand Angel Hotel. Reconvening with Haru, Yu learns that Kotona was in immense pain so she was sedated. Outside, Yu tries to warn Haru about the situation back in Evermore is affecting their world, which is proven by the fire at the Grand Angel Hotel. Still, Haru remains obstinate to Yu's pleas and elsewhere, Saki is confronted by the Black Hooded Man at her florist shop. The boys arrive just in time to save her and escape via her car and are pursued by the Black Hooded Man now transformed into a spider monster. As they're pursued, Yu elaborates on how the correlating lives are linked with one another. After Saki reveals that the Black Hooded Man inquired if she was "Sis Saki", Yu has an epiphany of the culprit behind everything. The spider using its web latches onto the car and gets on top of it. So, Saki manages to release it from its grip on the car, but in the process crashes the car into the river. This causes Yu and Haru to be transported back to Evermore.
In the throne room, Yu confronts Gnauss and calls him out as the traitor of the kingdom. Being called out by Yu and his speculation accompanied by it. Furthermore, Astrid's request to see Gnauss' body as the magic used to create the dagger that cursed her would leave an imprint on the creator's body. And Haru's suspicion of Galeroth's words, Gnauss then reveals his body, that's heavily influenced by dark magic. With the arrival of Barton, Gnauss summons a Black Banner Armor and that he's also Galeroth Felgrimm, leader of the Black Banner. But the revelations don't stop there, Gnauss also confesses that he's also Sedulus Astrum, Fidelius' older brother. Although he was killed by his father, he revived himself using alchemy and demon's blood. To top things off Gnauss reveals that he was surrendered to an enemy kingdom as a peace offering. Gnauss though found solace at the new kingdom, but was this was all crushed when his father invaded and destroyed the kingdom.
Now after the life of the princess, Astrid reminds Gnauss that if she dies he'll die as well due to her Royal Egis. To remedy this problem, Gnauss changes into Galeroth and enchants Haru's armor to his control. Manipulated by Galeroth Haru proceeds to kill Astrid, but is stopped and defeated by Yu. With the tides starting to turn on him, Galeroth takes Astrid hostage and escapes through a magic bubble out of the castle. Outside the castle and on its grounds, Galeroth attacks the castle making the rubble fall onto Astrid. This would circumvent the conditions of the Royal Egis on Astrid. Therefore, Yu uses his body to shield Astrid from the falling rubble and is impaled in the process. Yu is moved to the sidelines and is kissed on the forehead by Astrid. As Yu's conscious starts to fade, he sees the Old Man again, meanwhile, Haru and Astrid confront Galeroth, but are unable to fight on par with him. Back to Yu who then receives the real Mornstar from the old man, who then returns back the otherworld.
Desiring to finally end it all, Galeroth transforms into a giant four-legged monster, grabs Astrid, and attacks Haru. Before Galeroth could land the finishing blow on Haru, Yu uses the Mornstar to parry the attack. Galeroth then escapes to the sky and proclaims that once Astrid and his power combine, he'll be invincible. Just as Galeroth starts to drain Astrid of her power a giant black bird appears and using it, Yu rides it to Galeroth. Yu then severs Galeroth's left arm freeing Astrid from his grasp, but causing her to free fall from the sky. However, Yu manages to catch and save her, while being able to land safely on the ground. Going on a rampage, Galeroth and Yu fight and once the monster has Yu at his mercy, he notices that the Mornstar is missing. It's then that Haru leaps into action and uses the Mornstar to slay Galeroth.
Because Galeroth was defeated the Black Banner army retreats. In the place of where Galeroth was slain, a giant portal way to Yu and Haru's world was set. Astrid explains that once it closes they'll never be able to return back to their world. So to prevent this from happening, Haru and Yu go through the portal, but Yu decides to stay behind in the otherworld.
Back in his own world, Haru awakens in the hospital. Haru then desperately searches for Yu, but in the process finds Saki instead of whom emotionally embraces him. Saki reveals to him that he was out for a month and furthermore Kotona got surgery to get her tumor removed. When Haru mentions Yu, instantly Saki and Kotana lose their memories of Yu. Haru then gets an epiphany as he realizes that Yu was his link in another world. He then walks by a couple of memorial places that involved him and Yu as he wonders how Yu is doing in the other world.
After the credits, Yu is crowned the new king of Evermore and marries Astrid. Together, they live happily ever after.