Koishiki Kaikyuu

Sergeant Akasaka, a recent college graduate who joins the army after passing high-level exams, is assigned to learn about his unit from LP Oohori, a younger and lower-ranking soldier. After suggesting that Oohori take the army exam, Akasaka is raped by Oohori, who becomes angry at the suggestion. Despite the assault, Akasaka does not report the incident for reasons unclear. Oohori continues to sexually assault Akasaka as a form of "payment" for his training, leaving it uncertain whether this is solely Oohori’s motivation or if there is a deeper reason.