This Can’t Be First Love (BL manga)

Keiichi and Sota have been friends since elementary school. Despite Sota’s popularity with girls, he always rejects their advances, and even actively avoids them by hiding in the school nurse’s office. So when Sota starts getting along with Jou, a female student who also spends time in the nurse’s office, Keiichi feels a surprising twinge of jealousy. But it may be thanks to her that Keiichi comes to terms with how he really feels about his long-time friend…