Kore wa Akuma de, Mamagoto Dakara.

Souichirou moves in with his relatives after leaving his hometown. There, he reconnects with Miku, a distant relative and childhood friend. As children, they played pretend together, and now she suggests another game—this time, pretending to be a couple. They begin acting like a loving pair, engaging in playful gestures such as hugging and kissing. Over time, the game becomes more intense, blurring the line between pretense and real emotion. Neither is willing to acknowledge true feelings, as the agreement is that it must remain pretend. Their relationship grows complicated as they struggle to distinguish between the act and genuine emotions.