FIVE NUMBERS!

The story takes place in a isolated prison. A pleasant young man, a sexy woman, an ex-soldier middle aged man, a hacker girl, a mysterious old man and a cat are confined there. One day, they get freed after a blackout. Strangely, all the prison guards have disappeared and they cannot find the exit. Suddenly an extraordinary event occurs in response to the old man's weird behavior. — Description from AniList community (anilist.co).