It is an era in which humanoid, high-performance androids have become widespread. Their creator, the engineering genius Mitaka Ryou, spends his time researching and living alone with his androids. One day, he conducts an experiment to give Tsubaki, an android, feelings, which has been his dream for many years, but the experiment ends in failure. The next morning, however, Tsubaki suddenly kisses him affectionately and shows signs of emotion. Tsubaki soon learns about various emotions and begins to say and do things that deviate from the program, and his feelings for Ryoy begin to change...