After a sudden marriage proposal due to family circumstances, high school student Yuuichi finds himself betrothed to his classmate Watanae, a seemingly ordinary girl. With a firm belief in 2D heroines, Yuuichi is taken aback when he discovers Watanae's hidden otaku side and her surprising connection to his favorite fictional character. As they start living together, Watanae's endearing personality and secret identity as a voice actress gradually chip away at Yuuichi's resistance to real-life romance. Despite his initial reluctance towards 3D girls, Yuuichi finds himself drawn to Watanae's charm and the unexpected depth of their relationship, leading to a heartwarming and chaotic romantic comedy between the two unlikely fiancees.