Otomo Seiya (Oseki Yuta) proposed to Sasaoka Rio (Ikuta Erika). Rio once planned to resign as a class teacher, but with the encouragement of her students, she decided to cheer up and witness the graduation of the third-year Class C students.However, when she went to Seiya's house to talk about the matter, she discovered a shocking fact!

Rio rushed out of Seiya's house, and in order to drink away her sorrows, she met her sister Seri (Seiko Utsumi) and her father Hideki (Katsunori Takahashi) in Ginza.Before arriving at her destination, she saw a woman who looked exactly like her student Reina Sawai (Mizuki Kayajima), but because she didn't want to cause any more trouble, she pretended not to see it and left...

The next morning, Izumi Yuzo (Motor Fuyuki), a well-known complainant in the neighborhood, shows up at school.On the other hand, Reina did not appear in Class C of 3rd year, and Hikari Ohkito (Rio Komiya) was also late.Both are single-parent families, and both parents refused to participate in the tripartite talks.After discussing with the deputy head teacher Yamazo Kaito (Hayama Nobuyuki), Rio decided to visit their homes respectively. However, she heard that both parents had bad rumors, and Rio once again found herself in a dilemma and had to run into the toilet...

When problems came one after another, Rio received contact from Seiya many times, but she chose to continue to ignore it.One day, when she returned to her home, she found that Seiya was also there!?