Marumaro is a member of the Devee Clan, a race of yellow, humanoid creatures known for wearing pots as hats. He is the shadow wielder of Saber Tiger, a powerful feline-type shadow that favors monk‑style charged attacks. A distinctive verbal tic marks his speech: he habitually ends sentences with the word maro, and in the original game he uses maro in place of first‑person pronouns. His background begins in his home village within the first season, where the destruction of the village by the twin shadow users Ivanov and Gustuv drives him to join Shu and the others. By the time of Trials of the Seven Shadows, two years have passed and Marumaro has returned to his village. His shadow has been dormant until Noi uses a special ability to reawaken Saber Tiger, prompting a renewed involvement in the struggle against new threats.

Personality‑wise, Marumaro displays an immature and casual demeanor, often becoming preoccupied with attractive girls—Bouquet in particular—and his antics frequently irritate Kluke and Bouquet. Beneath this playful, sometimes lecherous exterior lies a genuinely kind and loyal individual who is always willing to help his friends. His shadow, Saber Tiger, sees itself as a champion of justice and encourages Marumaro to adopt the same mindset, gradually shaping his motivations toward a sense of right and wrong. Marumaro’s primary motivation is to protect his companions and stand up against injustice, a drive that strengthens as he bonds with the group.

In the story of Trials of the Seven Shadows, Marumaro serves as a core member of Shu’s party. He plays an active role in battles, using Saber Tiger to drive out Dragon Scales from afflicted characters and to fight against the forces of General Logi and the Investiture Beings. His key relationship is a competitive rivalry with Noi, sparked by Noi’s reawakening of Saber Tiger; the two frequently try to outdo each other. He also maintains strong bonds with Shu, Bouquet, Jiro, and Kluke, having fought alongside them from the first season.

Development through the series shows Marumaro maturing from a self‑interested trickster to a more reliable fighter who embraces Saber Tiger’s sense of justice. His notable abilities center on Saber Tiger, which delivers monk‑style charged attacks and can merge with other shadows (for example, combining with Bouquet’s Hippopotamus) to produce more powerful forms and techniques. Through his shadow, Marumaro contributes both offensive power and a touch of levity to the group’s dynamic.