Tatoe Toraware no Koi demo

Suou Hozumi is the over protected heir of the Suou family. His grandfather barely lets him out of the house, so when an accident brings suave Kanzaki Shougo into Hozumi's life, he can't resist the appeal of the kind older man. But innocent Hozumi has no idea what his new friend is capable of...

(Source: Houbunsha, translated)