Moriguchi Kyoichi holds the position of Vice President in Misumaru Middle School's student council. A black belt in martial arts, he possesses a fiercely volatile temper, frequently erupting into intense anger over minor provocations. This hot-blooded nature initially contrasts sharply with the calm demeanor of student council president Hachiyou Tsunamori. Despite his aggressive exterior, Kyoichi exhibits profound loyalty to his friends and gradually unveils a softer, more protective side.

Kyoichi commands explosive psychic abilities, though he initially dismisses their worth, plagued by significant self-doubt regarding their effectiveness compared to others. His perception shifts when Harumi Mineo reveals his powers are uniquely essential for activating Earth's giant protector, the Shingu. These abilities manifest as destructive bursts of energy, yet Muryou Subaru notes Kyoichi lacks precise control, labeling his approach "unskilled but strong."

A pivotal element of Kyoichi's past is the death of his parents during an Astral Deviation event. This loss fuels his initial hostility toward Muryou and intensifies his protective instincts toward Tenmo town. His character arc focuses on overcoming self-doubt about both his powers and personal worth. He learns to trust his role within the team of student guardians, embracing his feelings for Harumi. This emotional growth allows him to channel his powers more effectively during critical battles.

Kyoichi's relationship with Harumi Mineo remains unacknowledged by both at first, though their interactions increasingly reveal its depth. His eventual admission of feelings coincides with his broader emotional maturation. Throughout the series, his unwavering loyalty and fierce defense of others solidify his role as a key protector of Earth alongside his fellow student council members.