Ore no Mono ni Narinasai.

Kei is a well-known, charming model who is confident and popular. Despite his success and many admirers, he is interested in Nanami, his cousin and roommate. Nanami has a difficult personality at times, but Kei believes he is kind and caring, even if he struggles to show it. Kei finds this endearing and has made several attempts to win Nanami over. However, Nanami does not take these efforts seriously. Kei's strong desire for affection leads him to act possessively, making him both attractive and difficult to be around.