Gourmet no Fukurami

Namura Tsutomu has a special condition where due to calorie consumption, he gets a raging hard-on every time he eats. He gets help to cure his irregular erections from Kaiyama and Masaki of a human research institute, who find his condition fascinating. Things continue like this until he meets the handsome heir, Shiga Haruka, whose gentle touch seems to help him.