Dai Mugen is a bright, easy-going elementary school student who attends school with Kishi Kaisei and Sonosaki Susumu. He once passionately played the drums but quit, disillusioned, after losing a junior music competition to rival drummer Rin Tanba.

His life shifts dramatically when the self-proclaimed god Goutetsu falls from the sky. Recognizing Dai's hidden potential, Goutetsu recruits him as an "oyakata," a human coach for kamizumo—ritual divine sumo battles. In these matches, gods draw power from their oyakata's rhythmic drumbeats, forcing a reluctant Dai to pick up his drumsticks again.

Partnered with Goutetsu, a passionate stone god with a lion-like mane, Dai enters the world of kamizumo. He must channel his drumming to energize Goutetsu during combat. Through incremental victories, Dai confronts his lingering self-doubts about music, gradually reigniting his drumming passion within this new context. His journey focuses on overcoming past setbacks to reach kamizumo's highest level.

Dai maintains friendships like Susumu Sonosaki, a music enthusiast often listening on his smartphone. Kamizumo introduces him to other gods and their oyakata, including Rin Tanba, now master of the pen god Ryusho. Navigating this supernatural world, Dai's development centers on reconciling his failed musical past with his new purpose, using rhythm not just for competition but to empower divine combat.