Shinomiya-kun ni wa Wake ga Aru

In the story, Sora is the youngest child, raised among all male siblings, and is doted upon. But Sora (and the rest of the brothers) have a secret that they can't tell anyone. Update: According to the mangaka's Twitter account, due to the their health problems, this manga entered into hiatus past chapter 15, which was released in Japan on August 2019.