Onii-san

The male lead of the series, he is an ordinary office worker who has long struggled with the Monday morning blues that come with the daily grind. His uneventful commute takes an unexpected turn when a high school girl named Ai accidentally collides with him on the station platform, leaving him injured. In response to her heartfelt apology, he takes it upon himself to accompany her on the train every Monday, shielding her from the overwhelming rush-hour crowds. As their weekly encounters accumulate, his calm and steadfast nature gradually comes to light, and a sincere bond—one that transcends the gap in their ages—begins to quietly blossom between them, making him the emotional cornerstone of the entire narrative.