Yuuma in his old school uniform.
|Voice Actor||Shinnosuke Tachibana|
|Hair Color||Deep dark purple|
|Birthplace||Hayama, Kanagawa Prefecture|
Alma Jinnai (twin sister)
Yuuma Jinnai (神内祐馬 Jinnai Yuuma?) is Akari's crush and Alma's twin brother. Yuuma attends the same school as Akari and lives with his grandparents. He believes his mother died when she was young and it is presumed that his father has died too.
As the twin brother of Alma, he looked extemely similar to Alma (especially when she is in a male disguise) except he has shorter hair and a little higher strature than his twin sister.
Yuma is a hard-working and focused teenager, as seen he has been practicing basketball, his favorite sport whenever he is free. Although look cold on the outside, Yuma actually possesses a welcoming and warm personality that eventually lets himself to be near to Akari , which he sometimes find hard to express his own feelings towards her .
Yuma is also a very open-minded, not showing a sign of shock nor surprise when he find out the secret of Akari and the relationship between himself and the Jewelland. Instead, he is quite helpful to Akari when dealing with the problems with Alma, his long-lost twin sister.
In the beginning of the series, he appears withdrawn and quiet with everyone.While he is nice to Akari, he doesn't become friends with her until her birthday, which he invites her to come to his basket ball game. Afterwards, he is around her all the time and helps her with her problems. when Akari confesses to him that she likes him, he is shocked, but then blushes and smiles, indicating that he has similar feelings for her. Although he doesn't reply right away, it is obvious that he does harbor romantic feelings for her and finally confesses to her on Valentine's Day. In the final battle with Alma, he puts some sense into his sister's head that she is doing bad things and helps her revive their mother. In the final episode, he and Alma are now living together as siblings. Also it is indicated that he and Akari are a couple because when Akari visted him during basketball pratice he calls her "Akari" instead of her last name like he usually does.
- In the European Portuguese dub, Yuuma is voiced by Peter Michael, who is known for voicing Pinocchio in Nippon Animation's adaptation of Pinocchio, the first voice of Brock in Pokémon, Sasuke in Naruto and Sonic in Sonic X.
- He also voiced cartoon characters like Ferb Fletcher from Phineas & Ferb and Gorthan Destroyer of Light from Tom and Jerry: The Fast and The Furry.
- Peter has also been the voice of other characters since Twinkle, such as Tour, Rald, Alex, King, Coal, Moldavite, Mikage Shiraishi, Teacher Iruka and Retsu Akagi.