Akira Shimotsuki is Himuro Yukina's cousin. His parents died in a fatal accident when he was still a young child. He seemes to have a strong devotion towards his cousin Yukina because his life was saved by Yukina when he almost got hit by a car right after he heard his parents were no longer coming home. Akira is one of the only people who knows that Yukina is disguised as a cellphone novelist, Yupina. Akira is almost always seen eating food besides Yukina, such as melon bread.
Being Yukina's cousin doesn't stop him from being in love with her. He's never been apart from her since they were children. Yukina saved him from being hit by a car, therefore Akira has a strong devotion towards her, where she then promised they'd be together always. Ever since, Akira has long wished to be with his cousin, not in a cousin-love way, but a lover way. He wanted Yukina to see him as a man as well, which she soon does. He seems to sometimes be protective of her when Shigure is around. He often tells her that he does not want her to be around him anymore. He also has confessed that he is jealous also.
Yuki Kaji voices Akira in drama CD.