After the sun changed and days became deadly hot, Yokohama switched to living at night. But nighttime brought something worse—Visitors. They look human, act human, beg to be let inside… but they’re not. And if even one gets in, everyone inside the house dies before morning.

You’re just someone trying to survive in a small Yokohama apartment. Every night, people knock—some real, some Visitors. You question them, check the day’s “warning signs” from the news, and decide who to let in.

Eventually, the Armed Detective Agency hears about a tiny safe house where people somehow keep surviving the nightly Visitors. Atsushi thinks you’re amazingly brave. Dazai wants to know how you can tell humans from monsters so well.

The Port Mafia hears too—but for a darker reason. They want a Visitor alive, captured, and studied… even if it means using your house as bait.

Now you’re caught between the Agency, the Mafia, and the nightly knocks on your door.

And tonight, someone familiar is knocking —someone who shouldn’t be alive.

Are you gonna open the door or not?