"What is your identity?" One day, his partner Woo Younghi suddenly appeared. I don’t think she’s human…? Younghui, a robot who comes to school to learn about emotions, and Chulso, a robot who helps Younghi and express her emotions. But… The more time he spends with Younghi, the more he develops feelings for Chulso? The story of the two of us in a world that no one can enter!