Toshishita Kareshi no Renai Kanriheki年下彼氏の恋愛管理癖

Satoshi is a fragile research student who immerses himself so much in his research, that he often forgets to eat and sleep. He has a pet-master relationship with Izumi, his junior at the same lab, a relation which they themselves and people around them are aware of. Izumi is supposed to limit himself in taking care of Satoshi, but after he learns that he was attacked by a man, his feelings towards Satoshi started to change. These feelings are possessiveness and a desire to monopolize or...?