Shiki

Shiki is a character who appears in Kingdom Hearts 3D: Dream Drop Distance. She appears in Traverse Town and meets Riku, whom she asks for protection.

Development
Shiki, along with Neku, Joshua, Beat, and Rhyme are the first characters to appear in the Kingdom Hearts series who originated from something other than Disney, Final Fantasy, or Kingdom Hearts fiction, although they are from another game that is property of Square Enix, as well as being designed by Tetsuya Nomura.

Kingdom Hearts 3D: Dream Drop Distance
According to Joshua, Shiki and the others lost their existences and their souls were taken by the Reapers, but they were revived in Traverse Town and met with their partners. To return to their world, they must complete a series of games created by the Reapers.

Shiki first appears being attacked by Dream Eaters, but Riku comes to her aid. After saving her, Riku attempts to leave but Shiki tells him that he should accompany her and protect her, calling him a "knight". Reluctantly, Riku agrees and they travel together until Shiki runs off and Riku meets with a mysterious man in a black coat. It is later revealed by Beat that the man in black tricked Shiki, telling her that if she brought him Riku he would take her and her partner to their home world. Realizing that she was wrong, Shiki apologizes to Riku. Later, Shiki, Beat and Riku watch Neku, Rhyme and Sora on another Traverse Town, which was split in two by the mysterious man.

Later, Shiki is finally able to reunite with Neku. When they are about to take a break, they are attacked by Dream Eaters but are saved by Sora. When Sora introduces himself to Shiki, he tells her that Neku was looking all over for her and that he said that he "needed" her, embarassing Neku. However, Shiki thanks Neku, claiming that she was happy to be important to someone. Joshua appears before them and tells them that Riku and the others are fighting in the other Traverse Town, so they go the Third District to fight the Dream Eaters. Still, a Dream Eater runs away to another world and Shiki wonders if they failed their mission, to which Sora says that he'll find the Dream Eater for them. After thanking Sora, Shiki mentions that Neku has changed and become cooler and they all invite Sora to visit them in Shibuya one day.

Origin
Shiki Misaki is a character from Square Enix's . She makes her first appearance during Neku's first week of the Reaper's Game, partnering up with Neku to withstand the Noise. Shiki explains the basics of the Game to Neku, and how to survive it. Though the pair initially grated, they eventually began to develop a deep bond of mutual trust. It is eventually revealed that Shiki's body is not her own, but instead belongs to her friend, Eri, as Shiki's appearance was given up as her entry fee to the Game. After both Neku and Shiki completed the first week of the game, they found out that only one of them can return back to the real world, and it is eventually decided Shiki should return. Unfortunately, during the second week of the Reaper's Game, Neku finds out that Shiki was actually taken as his entry fee. Feeling guilty, Neku decides to win this game to save Shiki.