Namaiki Shoujo Kusurizuke

A pair of cheeky junior high school girls falsely accused a quiet-looking guy of molestation on a commuter train. However, the quiet-looking guy turned out to be a member of a Yakuza gang!? They were taken to an office, and with nowhere to run, they became the members' sex toys... Abduction, confinement, assault, **, **... They are made to realize the true horror of adults and the "unknown pleasures".

(Source: Melonbooks, translated)

Note: Released at Comiket 97