Delinquent Daddy and Tender Teacher, book 3
Tama Mizuki

Elementary-school teacher Hitsuji has been dating Hatoyama for a year now, spending his days peacefully with him and his adorable son, Hinata. The arrival of another spring ushers in Hinata's third year of elementary school, and this time his teacher isn't Hitsuji! Hatoyama and Hinata are understandably anxious about this, but it seems Hitsuji is grappling with his own feelings about the situation as well. Then, when someone from Hatoyama’s delinquent past comes back into his orbit, Hitsuji’s insecurities threaten to get the better of him. Will he be able to defend his place at Hatoyama’s side?