Tensei Maou no Juliet
転生魔王のジュリエット
A commoner magician at a magic academy, Haruto, begins a relationship with Princess Iris from an enemy nation after confessing his feelings to her. However, Iris shares her body with a demon king, and their union threatens to destroy the world. To protect her, Haruto resolves to eliminate her connection to the demon king and break the curse.