This is a love triangle between two friends Ryotaro and Haru, and a girl named Mirei. They are all 15 years old and entering high school. The two boys run into Mirei outside of school and are both mesmerized by her, and soon they find out she is in their class! Mirei turns out to have "experience" in love matters, while the two guys are completely innocent. What will happen as the three of them gravitate towards each other?