Haruma Kagutsuchi led a Monster Strike team in Kaminohara alongside Aoi Mizusawa, Minami Wakaba, and Akira Kagetsuki before Ren Homura joined. He departed prior to Ren's arrival, creating the vacancy Ren later filled. Haruma recruited Akira Kagetsuki roughly one year before Ren returned, recognizing Akira's combat abilities and strategic approach to battles, particularly his skill in reading enemy attacks. This led Haruma to propose Akira's inclusion to Aoi and Minami. They were initially reluctant, but Haruma had deliberately held the team's fourth position open for a suitable candidate.

After leaving this original team, Haruma formed a new Monster Strike team with Kobayashi Mariko, Ichinose Shino, and Owada Kaoru. During this time, his behavior towards his former teammates and Ren became notably cold and distant. This change stemmed from external manipulation; he was brainwashed under the control of a monster named Memento Mori, which compromised his autonomy and relationships.

Physically, Haruma possesses a noticeably tanned, ambiguously brown complexion despite his parents having fair skin, and he has a deep, baritone voice. His leadership qualities and combat prowess are consistently highlighted, establishing him as one of the strongest Monster Strike players depicted.