Artist's commentary
A story about receiving a tiny-boob job from Koishi-chan
C'mon, let's get hard.
Other versions are in the FANBOX
https://husuhusu.fanbox.cc/posts/2392895
The title of this one has a portmanteau pun of "ちっぱい" which is slang for small breasts and "パイズリ" which is titjob. My brain's too fried to try to navigate even that simple of word play so I'm gonna hopefully leave it for someone else to come up with.