Baito-saki no Senpai ga Koukousei Janakatta Hanashi

Yari Tono (20) goes out to dinner with Waka Soyo (probably a high school student), a baby-faced senior who works at the café where she works part-time, on the advice of the manager. There she discovers that Waka is actually a grown man, four years older than her. Tono is puzzled by this shocking revelation, but... what if the senior guy at his part-time job is not actually a high school student?