When Yamada and Miyamura casually embark on an investigation to identify Yamada's first-year girlfriend, an email buried in Yamada's phone leads them to Hino--a timid classmate who has photos from when everyone lost their memories! But will that hard evidence actually answer any questions, or just stir up new ones? It will be up to Yamada to determine how far he's willing to go to dig up the past, especially one that might be better off forgotten...