The Forbidden Zone

(Two powerful leads + two male leads + infinite-world space adventure) Everyone is required to enter the Restricted Zone at the age of eighteen.

The worlds all exist in parallel, yet people can draw from each the things they desire. Humanity, once stripped of everything, gradually established a new system to fight back as time passed, while desperately searching for the person who could break the deadlock.

At first, everyone thought all they had to do was survive. But the further they went, the more they felt something was wrong. Was the place they were in really their world...?

There are monsters, ghosts, and all kinds of other elements, born in the universe to treat humans as both entertainment and food. A timid bottom who panics at the sight of ghosts but has boundless stamina × a slow-to-warm, cool-headed top whose combat ability keeps skyrocketing. Most of the supporting characters are sweet on the surface but dark underneath, or dark underneath and darker still. Everyone's got a black heart... (There's also a little comedy.)