Bokutachi wa Benkyou ga Dekinai: Nagisa ni Usemono Arite Senjin wa Enzen to [X] Suru
English title: We Never Learn: BOKUBEN - The Predecessor [X] with Elegance with the Missing Item on the Beach
Japanese title: ぼくたちは勉強ができない「渚に失せものありて先人は艶然と[X]する」
Type: OVA
Episodes: 1
Source: Manga
Genres: Comedy, Romance
Studios: Silver, Arvo Animation
Producers: Aniplex, Movic, Shueisha, BS11, ADK
Duration: 25 min
Rating: PG-13 - Teens 13 or older

The episode adapts chapters 48 and 49, which follow Yuiga and Asumi going on a fake date, and Yuiga encountering his teacher Mafuyu Kirisu after she accidentally loses her swimsuit top.

(Source: MAL News)