A Pair of Childhood Friends Who Were Put into One of "Those" Rooms

Seiji and Mai are childhood friends. One day, they wake up to find themselves in a room they often see online where they can't get out until they do something, a room they can't get out of. Seiji has no idea what a room you can't get out of until you do something is. Mai is curious about Seiji, so she doesn't want him to know what kind of room it is. Will the two of them be able to get out of this room? The condition to get out of the room is... is it that after all?