Shizuka Urumi reluctantly becomes a high school teacher; she resolves to stay out of student affairs but soon loses her temper at a certain pupil.

Shizuka's class starts arguing when a love affair between students is uncovered; she scolds one of them, which leads to a terrible situation.

After the teachers are asked to downsize the student body, Shizuka learns that one of her students, Keita Miyazawa, is in danger of expulsion.

Posters making a terrible claim about Shizuka cause a commotion at the school; Kaito faces expulsion on suspicion of physical assault.

When an old photo showing evidence of students smoking spreads at school, Seira, the students' teacher at the time, tries to avoid the issue.

Only Iroha faces expulsion for the smoking incident; as the students' frustration at the unfairness hits a breaking point, Shizuka's past is revealed.