For most parents, their child's teenage years are just as bad, if not worse, than the terrible twos. But for Sachiko and Masato Azuma, the situation is further complicated by their son Hikaru's autism. As puberty strikes, Hikaru's growing sexual awareness creates uncomfortable and embarrassing situations, and begins to affect his little sister, Kanon. The already-taxed Sachiko must find ways to alleviate the situation, while being mindful of the effects her approach may have on her children and on the people around them. But when Masato is told he has to relocate again for work, the pressure is really on Sachiko as the decision is made to move in with her mother-in-law, who has always been less-than-accommodating to Hikaru's needs. With new challenges arising daily - Hikaru tackling adolescence through the lens of autism, Kanon struggling with peer pressure, Masato throwing himself into the new job - will Sachiko, the Azuma family's rock, succumb to the cracks that have begun to form in her generally cheerful outlook on life?