Arisa has just arrived at Seven Arts as a new idol. However, she is immediately made to participate in an underground, risqué “idol competition event.” Ibuki, who knows nothing about what’s going on, struggles desperately and puts herself on the line to protect her junior Arisa. However, she ends up being overwhelmed by the various challenges. Meanwhile, Koharu from the idol unit mocks her while becoming involved with Kurozuka… And in the end, Ibuki comes to learn the truth about Arisa—the very person she tried so hard to protect…!