Love Generation - Season 1 Episode 7 Unfaithful
Overview: Sanae finds out about Soichiro's affair with Nami. Nami thinks that she'll be able to make Soichiro suffer like she did, but to the contrary, he chooses to give up everything for Sanae, which is something he never did for Nami. However, the damage is done and Sanae is put in an awkward predicament when her classmates bring up her wedding. Riko, on the other hand, finds out that Teppei hides something from her.