Haruma Kagutsuchi is a character from the Monster Strike The Movie who originally led a Monster Strike team in Kaminohara alongside Aoi Mizusawa, Minami Wakaba, and Akira Kagetsuki. His time with this team occurred before Ren Homura joined, as Haruma departed prior to Ren's arrival, leaving a vacancy that Ren would later fill. Prior to his departure, Haruma demonstrated keen leadership and strategic judgment by recruiting Akira Kagetsuki roughly one year before Ren returned. He recognized Akira's combat abilities and particular skill in reading enemy attacks, which led Haruma to propose Akira's inclusion to Aoi and Minami, who were initially reluctant. Haruma had deliberately kept the team's fourth position open, waiting for a suitable candidate.

Physically, Haruma is distinguished by a noticeably tanned, ambiguously brown complexion despite having fair-skinned parents, along with a notably deep, baritone voice for someone his age. These traits combine with his consistently highlighted leadership qualities and combat prowess, establishing him as one of the strongest Monster Strike players depicted.

After leaving his original team, Haruma formed a new Monster Strike team consisting of Kobayashi Mariko, Ichinose Shino, and Owada Kaoru. During this period, his behavior toward his former teammates and Ren became notably cold and distant. This dramatic shift in personality was not a natural change but rather the result of external manipulation. Haruma was brainwashed and placed under the control of a monster named Memento Mori, which compromised his autonomy and affected his relationships with those who had once been his allies. This brainwashing serves as the central explanation for his antagonistic behavior and cold demeanor. His development within the story revolves around this loss of agency and the consequences of being controlled by an external force, turning a once-respected leader and powerful player into an adversary. His notable abilities are rooted in his exceptional strength as a Monster Strike player, with his combat skills and strategic approach to battles being recognized by teammates and opponents alike as among the strongest in the setting.