You can read Kuro's main story here: https://bato.to/title/184690-requesting-man-tits-fucking-total-masochist-kuro-kun-silly-while-teasing-his-sensitive-nipples

Bottom-on-bottom clothed sex without going all the way
Shiro and Kuro attend the same university.
They work at the same part-time job as well. They work at a sex shop (specializing in house calls). Shiro scouted Kuro, who had interest in that kind of part-time job for a while.

The two hadn't spent much time together since the scouting, but one day, Shiro found out that Kuro had been requested. Overwhelmed with interest, Shiro questioned Kuro relentlessly on how it went. "I'm not sure whether my customer service was good or not," Kuro confided in Shiro as his customer saying he had given him a "cold reception" weighed on his mind. This was when Shiro proposed, "How about I re-train you with a practical demonstration?"

It was meant to be training, but the two's conduct gradually escalated... Shiro, who occasionally tops but generally bottoms, and submissive solely bottom Kuro. Please enjoy as they use toys to have bottom-on-bottom clothed sex.