Kangoku Senkan / Prison Battleship

Hentai is based on the first part of the eponymous adult game from Lilith Studio.

The action takes place in the near future, when humanity has successfully explored space and populated the entire Solar system. Due to population growth, the number of criminals has also increased, for which there was no place on Earth. Special space fortress prisons were built for such people.

Commander Bishop Leary and her assistant Major Naomi Evans went to one of these stations to conduct an inspection and identify illegal activities. However, on board the prison ship, they encountered men who were deprived of female companionship. They immediately devised a plan of conquest.