Ruka

Ruka, who is Ema younger sister and Mizuki older sister, is as popular as an idol and is always surrounded by people. But everything changes now that the two sisters have learned that Mizuki has found a girlfriend and that the spring of youth has finally arrived. Eventually his annoyance at the situation was reflected in his actions, which became even more aggressive against his little brother. They couldn't tolerate the thought of it being taken from them.