She is Mine

Three 15-year-olds—Ryotaro, Haru, and Mirei—are entering high school together. While walking outside school, the two boys encounter Mirei and are immediately captivated by her. They later discover she is in the same class as them. Mirei is described as having prior experience with romantic relationships, whereas Ryotaro and Haru are portrayed as inexperienced. As they spend more time together, a love triangle forms between the two boys and Mirei.