Being a super-fan isn't glamorous, it's nosebleeds at live shows and every spare yen going to merchandise, and this show gets that without flinching or judgment. Eripiyo's obsession is real, messy, sometimes unhealthy, but the show never punches down at her for it. What makes this work is that ChamJam actually deserves the devotion; watching an underground group that nobody cares about suddenly matter to someone changes what fandom means, and by the end you're rooting for both the idol group and the girl who believed first.

Eripiyo lives for ChamJam, a minor underground idol group based in Okayama Prefecture, and above all for Maina, its shy, lowest-ranked member. After Maina hands her a flyer and she sees her perform, Eripiyo gives her life over to supporting her. In her signature red tracksuit, she becomes known as Maina's one unrivaled fan and turns up at every event, from concerts to tiny fan meetups in remote places. Her enthusiasm runs so high that one performance leaves her with a massive nosebleed, and neither an injury nor Maina's seemingly cold attitude slows her down. Her dream is to see Maina take the stage at the Budokan, the famous Tokyo venue. The show is a comedy with music and slice-of-life elements about the lengths one super-fan will go to for the idol she loves.