放課後に乱れる姉教師と隣の部屋で喘ぐ妹 ～ 恋人になった女の子が、知り合いの嫌な男に寝取られる ～

The protagonist, Hirose Yuzuru, was an ordinary student. He studied and worked on his part time job like everyone else, and was content with his monotonous life. But there was just one thing he wished to change. He wanted to get closer with Aizawa Haruka, the woman he fell in love with from the time he enrolled in school. “Getting into a relationship with her, a teacher, is an impossible dream,” he thought to himself resignedly. So he continued his unchanging everyday life along with his classmate cum Haruka’s sister, Aizawa Yuuka; and the junior at his part time job, Usami Akari.