Moriya Kazunari works as an accountant at an advertising company. For a long time, he's had feelings for Tsujimura Arata, who he used to be classmates with in high school; Arata happens to be working at the sales department.
Moriya's serious and easily irritable, so while Tsujimura's easy-going and friendly nature tends to upset him, he can't seem to discard his feelings for him.
One day, when they're the only ones to stay behind at work, a sudden blackout leads them to lose consciousness.
When they come to, they're in a hotel room with no means of exit.
Their confusion only grows when a mysterious voice tells them to follow its orders if they want to escape...

[Translated from official website]