Itazura na Te wa Gaman ga Dekinai

Kubo, a university student who works at an adult goods store, is extremely curious about adult toys. One day, the store manager gets sick and Sugiura, a man who had piqued Kubo's interest when he'd been at the store before, comes to cover for him. While stocking shelves, Sugiura picks up a vibrator, and when Kubo casually teases him about using one, the usually expressionless Sugiura gets red and flustered... His subtle sensuality... Does that mean...? Taking a chance while they're alone in the back, Kubo pushes Sugiura against the wall, and...! Brought to the brink by a whirring toy! A wet 'n' wild love story between a simple-minded, arrogant student and a hot-and-cold prince!

(Source: Renta!)