Marin is going to do a group cosplay with her idol, the cosplayer "Juju," whose real name is Sajuna Inui, and they're going to cosplay as Black Lobelia and Black Lily from the magical girl anime "Flower Girl Blaze!!". Wakana heads over to Marin's home so that he can borrow the "Blaze!!" DVDs for research to make the outfits for them.

Juju's photographer and younger sister, Shinju Inui, meets Wakana and Marin for the first time. They're shocked at how opposite her appearance is to Sajuna, but they quickly become closer when they excitedly talk about cameras. Later on, Sajuna suggests that they check out the abandoned hospital that they'll be using for their group cosplay but...