Artist's commentary
The girl on class duty is used by the boys to practice fingering during recess
It seems the boys' silly game of competing to see who's the best at fingering was quickly banned for keeping the girl restrained and preventing her from doing her class duties.
High res, version diff, additional pages and raw files are relased on support sites.
【FANBOX】
https://www.fanbox.cc/@tsukimotokizuki/posts/6330518
【ファンティア】
https://fantia.jp/posts/2095716