As expected with Disney's D23 event taking place in Tokyo, Japan this weekend, more of Kingdom Hearts III, Square Enix's upcoming crossover RPG, has been revealed. During a special event held in Disneyland the publisher showed a new trailer which confirmed there will be a new Monsters Inc world in the game.

The trailer opened with Sora, Donald, and Goofy meeting Marluxia, a member of New Organization XIII. The character was first introduced in Kingdom Hearts: Chain of Memories, but this is his debut in a mainline entry in the series. Although Marluxia knows about Sora and the gang, they're not familiar with him. After this, the video brings in Sully, Mike, and Boo of Monsters Inc fame.

Of course, Sora has been transformed into a monster version of himself, and now sports furry blue skin and red spiky hair. Donald now has a single eye, much like Mike, while Goofy's monster transformation is ... goofy looking.

The trailer transitions into quick cuts between different sections from throughout the game, and we're given very fleeting glimpses at the Tangled world and The Little Mermaid's Ariel making an appearance, as well as Vanitas, the Keyblade wielder that made his debut in Kingdom Hearts: Birth By Sleep.

The trailer also showed Rapunzel, who interacts with the world by swinging her hair. She uses it to traverse environments and can also whip enemies with it. According to Square Enix she has a number of ways to use her hair in the game. There's also a new minigame styled after a Game & Watch title, but an official name for the game hasn't been revealed yet. Check out the full trailer above.

During the event Square Enix revealed some further details about the game, including that Gummi Ship segments will return. This time, however, it has been split into two phases. There's an exploration phase, which was likened to being more open-world, and there's a combat phase. Combat has been increased in scale, with more enemies than ever before.

According to Square Enix, everyone in the Osaka studio is working on Kingdom Hearts 3, with 100 people from its Tokyo studio also involved. Development is split into three sections: Early, middle, and late. There's around three worlds per section, but Square Enix noted that this doesn't mean there's nine worlds in total. The early phase worlds are 90 percent complete, while middle section worlds are at around 60 percent. It didn't confirm what stage the end section is, but Tetsuya Nomura, director of the series, said it was "something he's always wanted to do and put into Kingdom Hearts, ever since the days of working on Final Fantasy." He added: "It is bound to surprise everyone."

Finally, Square Enix confirmed that Utada Hikaru will be returning for the third game's theme song, which is called "Don't Think Twice." You can hear the song in this second new Kingdom Hearts 3 trailer, which ends with Rikku leaving his Keyblade behind for the other version of him to use.

It's been an incredibly long wait for Kingdom Hearts III, which concludes the story of the trilogy. Kingdom Hearts II was released way back in 2005, though there have been some spin-offs and remakes in the meantime. Kingdom Hearts III promises to be exciting for many reasons, including the larger party size (you can now have up to five members at once), new Keyblade transformations, summons that are based on Disney theme parks, and the introduction of the first Pixar world (Toy Story). Other new worlds include those based on Big Hero 6 and Tangled.

Notably, Kingdom Hearts III is coming to Xbox One in addition to PS4; no previous entry has been released on an Xbox platform. The game is still without an exact release date, though it is due out sometime in 2018.

Director Tetsuya Nomura--who is also working in that role on Final Fantasy VII Remake--explained the extremely long wait last year, saying there were numerous factors, including a change in engines. As for directing the two games at once, he actually thinks it's proven advantageous for him.