Mā-kun is a minor character appearing in arcade game centers throughout the series. Introduced as 13 years old in earlier timeline segments, he ages to 14 later on, possessing brown hair and black eyes.

He frequents arcades with his girlfriend, "Raging Girl." Both habitually erupt in frustration, throwing visible tantrums after losing versus matches, a consistent behavior across their appearances.

During his arcade sessions, Mā-kun is depicted playing the character Nakoruru Ken from *Samurai Spirits*. His in-game sprite visually resembles Haruo Yaguchi, a main character, though they remain distinct individuals within the narrative.

Mā-kun's role stays confined to background interactions in arcade settings. He receives no significant character development, backstory expansion, or involvement in major plotlines across seasons, OVAs, or spin-off media.