Aki Sora is a manga written by Masahiro Itosugi. After a controversial revision of Tokyo Metropolitan Ordinance Regarding the Healthy Development of Youths, in a Q&A section about that revision, authority listed its first and third volume as one of six examples of violation over the revised law, thus publisher of the manga series decided to terminate the series' publication.
Ever since he was a young child, Sora Aoi had always exchanged words of "I love you" with his attractive older sister Aki. Now, as he comes of age, he finds it much harder to exchange such comforts as they did in those simpler times. When Aki demonstrates her feelings toward him to go beyond a sister's love, Sora finds himself questioning his feelings for his sister. Realizing their affection for one another, they consummate their love in secret. In a society that would never understand, they must now keep their love a secret from their family and everyone they know. However Sora soon finds himself exploring many forms of love not accepted by society and questioning his feelings for his sister.