17 parts Ongoing Rini is a small, delicate, and fragile girl who has been moved to Nanba prison. She has many sleep disorders, chronic fainting, and night terrors. Her origin is unknown, but it's something that's not really pretty.
She's been placed at building 13, cell 13 and been called inmate 50. There, she meets 4 inmates named Jyugo, Uno, Nico, and Rock. Later, she meets all the other inmates and guards at Nanba prison.
Now, Rini must learn to embrace and adapt to her new environment around her, and let her newfound friends to help her uncover her origins. Otherwise, very bad things will come for them and the entire prison too.
(This story has a reverse harem)