Inamoto Momoka is a girl tasked with sealing monsters that spread across the world and bring disaster into special cards. With constant support from her best friend Tokudaiji Tomoko, she continues her daily battle of capturing these creatures. One day, the lightning monster Raima and the tentacle monster Shokuma—both of which would normally flee—suddenly attack. Momoka struggles but manages to capture Shokuma, yet is overpowered by Raima and forced to retreat. Badly injured and with her costume torn to shreds from the intense battle, Momoka returns to Tomoko. Seeing her condition, Tomoko cries out in despair, telling Momoka to strip off her damaged outfit right there and invites her to take a shower. As Momoka lets the shower water wash away the heat of battle, she suddenly hears Tomoko's scream from the room. Rushing back wrapped only in a bath towel, Momoka finds Shokuma's tentacles emerging from the sealed card, wrapping tightly around Tomoko.