It's already been 2 years since they started dating. Shoko (Sasakura) had begun to think about marriage with her colleague teacher Tadashi, but the crucial Tadashi wouldn't propose, leaving her feeling anxious day after day. At such a time, a single email from former student Aimi (Abe) arrives on Tadashi's phone... Though she knows it's wrong, Shoko secretly peeks. There she finds a blackmail message along with an attached photo of Tadashi touching the buttocks of Eri (Maeda), who was also a former student...
