Yūdai possesses a serious and gentle demeanor, coupled with notable shyness and a somewhat wimpy nature. He grapples intensely with expressing his true emotions, especially those directed at Chizuru, for whom he harbors deep affection. Despite the strength of his feelings, an inherent timidity and fear of rejection render him incapable of voicing "I love you."

This romantic difficulty stems from a broader pattern of insecurity within relationships. A history of unsuccessful romantic pursuits fuels his current hesitance and pervasive self-doubt. This emotional vulnerability intertwines with a mutual fear of emotional pain from past failures, constructing a significant barrier to open communication between Yūdai and Chizuru.

During a pivotal Christmas moment, Yūdai attempts a gesture of affection by planning to gift Chizuru a rabbit concealed within a box. This plan unravels when the rabbit escapes unexpectedly. The incident exacerbates the existing misunderstandings and emotional distance separating them.

The narrative unfolds the same events through both Yūdai’s and Chizuru’s perspectives, emphasizing his internal turmoil and desperate attempts to conquer his cowardly tendencies. Paralyzed by the fear of losing what matters most, he remains ensnared by his insecurities, perpetuating a cycle of misinterpretations that pushes their relationship toward collapse. His character arc centers entirely on this struggle to confront his fears and bridge the emotional gap with Chizuru before their connection fails completely.