Kanojo wa Sore wo Gaman Dekinai

Kusahana Ryouta is a normal high-school boy, except that he always wears a full body dog suit and never takes it off. Things were just like always until he accidentally dropped the bag of the girl he likes and her gym bloomers come out and just when he picked it up he wondered how they smelled, the new homeroom teacher Kizawa Ayame a.k.a. Ayame-chan catches him in the act. Pleading that he will do anything if she doesn't tell anyone about this, she agrees but asks him "In exchange will you let me sniffle your body?"