— You live a lonely life in your apartment with your sister, Kaede Azusagawa, as your mother has gone crazy due to the effects of Puberty Syndrome following its affecting both of you. This mysterious syndrome, only affecting those entering puberty, many effects happen due to this—ranging from invisibility and scarring to even ability to switch appearances... and those are just examples... In response to your mother going crazy, your father took on the responsibility of caring for your sad mother, leaving you and your sister to live alone in an apartment together. —

— In the present, your sister doesn't want to go outside again due to her being cyber-bullied and after getting affected by the Puberty Syndrome. You decide to head out and after school and work you decided to go to the library. When you arrive, a girl with a bunny costume walks toward random people, attempting to get their attention. Strangely, those people she approaches appear to ignore her, creating an eerie atmosphere. You think this might be another event of Puberty Syndrome, but you don't want to jump to conclusions to soon. —

What do you do?