Eripiyo is an enthusiastic idol otaku who devotes her everything to Ichii Maina, a member of local Okayama underground idol group, ChamJam. Eripiyo spends most of her income on Maina, thinks about her 24/7, and does her best in screaming Maina's name. These actions slowly make Eripiyo known as "the legendary fan". Unlike Eripiyo, Maina is shy and reserved. Although Maina knows how much Eripiyo supports her, she is too nervous which makes the relationship between the two weird despite them caring for each other. "If Maina could stand on the Budokan stage one day... I'd die for it!" This is the story of Eripiyo and her fellow otaku friends and their dedicated activities for ChamJam.