Senpai, Would You Like to Try Cheating With Me? ~My Childhood Friend Was Stolen By My Best Friend, so From Now On, I'll Steal My Former Best Friend's Younger Sister in Return~

Synopsis

High school student Naegi Toshiya one day happens to witness his girlfriend Tsukimiya Airi and his classmate and best friend Nakajo Shintarou coming out of a love hotel. Toshiya can't hide his shock at being cheated on. At that moment, the one who appeared before Toshiya was Rinka, a younger girl who was also Shintarou's sister. 「Senpai, would you like to try cheating with me?」 What she proposed was a revenge plan──to cheat in return and give them the same pain. Though Toshiya initially refused, he couldn't keep turning down Rinka's aggressive advances, and eventually they ended up in such a deep relationship that there was no turning back...? A forbidden "revenge cheating" romantic comedy between "me", who had his girlfriend stolen, and a yandere kohai beauty, begins here!