Keisuke Katagiri is a student at Shimizu South High School and a supporting character in the Haruchika series. He is a second-year student and serves as the president of the school's wind ensemble or band club. As a brass player, his chosen instrument is the trumpet.

In terms of his physical appearance, Keisuke is depicted with bowl-cut brown hair and brown eyes. He is typically seen wearing the standard school uniform.

As the club president, Keisuke holds a position of responsibility within the band. When first-year students like Chika Homura and Haruta Kamijou join the club, they are introduced to Keisuke as the president. His role places him as a leader among the student members, overseeing club activities and representing the ensemble. The band club itself is initially very small, with Keisuke being one of its core members before the arrival of new students.

Within the story, Keisuke is involved in the various mysteries the club encounters. For instance, he is present when the club discovers a cryptic message and musical notes painted on the blackboard in the music room, an event that launches one of the group's first investigations.

Specific details about his personality, personal motivations, character development throughout the series, and the full extent of his key relationships are not elaborated upon in the available information. Similarly, while his general abilities as a trumpet player can be inferred from his position as a member and president of the concert band, no specific notable abilities are detailed. The search results focus primarily on his basic biographical status as a second-year student, the club president, and a trumpet player.