Tatsuki Fujimoto 17–26: Mitsuko and Kyoko Ebara

They're sisters who are competing each other for the best nude painting at their school for its annual art competition once per year as part of its tradition. Mitsuko is the older sibling, and Kyoko is the younger one. After finding out her little sister won that year's art contest thanks to the naked painting of her older sister, Mitsuko decided to do the same on Kyoko just to win and to get her revenge after enduring relentless teasing and humiliation from her classmates due to her being in her birthday suit in front of everyone. Even after Mitsuko won the next year's art contest with a better painting of herself, she ended up living with her sister at Tokyo after moving out of their house.