Despite being Makoto's age, she couldn't be more different: Erio chooses to wrap herself in a futon all day rather than to go to school. Upon moving into his aunt's house, he discovers the cousin he never knew about: Erio Touwa. However, as ordinary as he had imagined his adolescence to be, he could never have taken the existence of an enigmatic long-lost cousin into account.
When his parents go overseas, he moves to a new town to live with his aunt, welcoming the change and ready for a fresh start. Makoto Niwa meticulously tallies the amount of positive and negative youthful experiences he engages in as if to grade his own life.
