Ganmo is a pink chicken-like alien creature from another planet. He arrives on Earth inside a strange egg discovered by Tsukune Tsukuda, who brings it home to her younger brother Hanpeita. After hatching, Ganmo begins living with the Tsukuda family and possesses the ability to speak human language.

Physically resembling a bird with wings, Ganmo frequently engages in human-like activities. He demonstrates persistent eagerness to assist the household, regularly undertaking chores such as running errands and cleaning. However, his efforts often result in comical blunders and accidental destruction. Despite these mishaps, he remains determined to improve his standing within the family.

Ganmo develops a rivalry with Déjà Vu, a myna bird owned by Ayumi Ichigaya, the Tsukudas' new neighbor. Déjà Vu mocks Ganmo's unusual appearance, sparking ongoing tension between them. This dynamic complicates Ganmo's attempts to integrate into daily life with Hanpeita and the Tsukuda family.

His presence significantly disrupts the household's ordinary routines, amplifying existing chaos through well-intentioned but flawed interventions. Interactions between Ganmo and the human characters drive many situational challenges encountered throughout the series.