Kanojo wa Sore wo Gaman Dekinai

Kusahana Ryouta is a normal highschool boy, except that he always wears a full body dog suit and never take it off.

Things were just like always until he accidentally dropped the bag of the girl he likes and her sports pants comes out and just when he picked it up he wondered how they smelled, the new homeroom Teacher Kizawa ayame AKA Ayane-Chan catches him in the act. Pleading that he will do anything if she don't tells anyone about this, she agrees but asks him "In exchange will you let me sniffle your body?".

(Soure: MU)