Yano Reiko is a part-time student. After being introduced by a well-known classmate, she becomes the tutor for Mariko, the second daughter of the bourgeois Todo family. The eldest daughter of the Todo family, Tomoe, is a typical bourgeois lady who secretly loves Fuyuhiko Kanae, an architectural engineer who is designing her villa. For Reiko, the life of the Todo family is completely different, but when she meets the bright and intelligent Fuyuhiko, she feels more than just affection for him, going beyond Reiko's circumstances. Meanwhile, Fuyuhiko also begins to love the neat and beautiful Reiko. The relationship between the two develops rapidly, but Reiko's heart is complicated. This is because Reiko has an older sister, Ginko, who works in a red-light district...