https://www.pixiv.net/user/7557550/series/209875

Intro: The story of the girls who have been made sex slaves. Sexual acts that you rarely feel, such as pleasure, and the days of training ... Chewing on the limbs, the collar is fitted, and it is detained naked in the other way and it is a spectacle ...
The girl does not fall into pleasure

or

The story of the girls who were suddenly slaves one day, even though they were ordinary everyday life. Service and training days ... The limbs are shackles, the collar is fitted, the nipples are passed through the piercings, and the other is restrained and managed by a naked and narrow cage.

Translator of the Introduction: @jonnycashmoney

Japanese version:
01-65: https://eh.makinico.moe/g/2983471/c150cf0d0e/
66-124: https://eh.makinico.moe/g/3206608/16e9a1654e/
125-189: https://eh.makinico.moe/g/3528297/dc3cb1cb32/
190-248: https://eh.makinico.moe/g/4189647/6a5ae84187/

English version:
161,165-189: https://eh.makinico.moe/g/2983471/c150cf0d0e/
190-248: https://eh.makinico.moe/g/4189648/b1de320602/