I've recently came across this book and I accidently logged out while reading. It's about a guy who hides the fact that he has a sensitive body and he thought working out would be the cure. He encountered a guy who heard him jerking off once who appears to be his trainor and now teases him. The character's name is Param and the trainer is red-haired.
Furudate is definitely an artistic and narrative mastermind. From the panels, to the story and the characters, all never ceases to amaze a fellow reader like me. I highly recommend reading ALL their works. :3