Koishite Daddy(2011)

Satou is a salaryman who is raising Rintarou, a toddler, by himself. After an event, he gets closer to his neighbour, Takahashi, a gay university student. Satou begins to get attracted to Takahashi who is fond of children and helps Satou a lot, but he held himself back thinking it would be too imprudent for him since he only got divorced just recently. Yet Rintarou starts throwing tantrums wanting to go to Takahashi's house all the time, and Satou is confused... What is going to happen? Here's a cute and sweet family story!