Always cheerful and seemingly fearless, but pooping is her one absolute taboo. She is so shy about it that she once held it for 98 hours. That's how extreme she is.

Indifferent and rarely listens to others. However, she knows how to have a good time when playing. She has no shame and acts recklessly, but even Tsuki finds pooping embarrassing.

Has no sense of shame, not even about pooping. She's a bit obsessive and loves hanging out. She likes singing and gets upset if people don't talk to her.

Miku's older sister. She teases Miku no matter what she does, and pooping is no exception. If Miku so much as visits a restroom, Riku will tease her for a whole year.