Zenjitsu is so funny, still I can't believe Zenjitsu would just give up on coming to the training like that. I mean even if he's recovered, it's still a chance to interact with girls that would never even give him the time of day.
I imagine after they started improving Kanao became their only playmate so that would mean Zenitsu wouldn't get a chance to play cool in the teacup game or to grope the girls when playing tag and i don't think they would allow them to hang out in the training room just chilling with the other girls so that's why Zenitsu gave up
Surprised there's no Cultured Master who'd list all the series name the heroines are in already..
I only know Nezuko (obviously) and the spirit girl Yuuna from "Yuuna and the Haunted Hot Springs".
Second to the right, from top left. Long white hair. Floating in the air.
MD link for those interested: https://mangadex.org/title/18258/yuragi-sou-no-yuuna-san