Underworld Restaurant is a Manga/Manhwa/Manhua in english language, manhwa series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

“8, 8, 8, 8.2 billion?!” 8.2 billion buildings suddenly appeared in the life of earth spoon!! And... restaurant? The behavior of the customers who come to the restaurant is suspicious, and they say only unknown things... … . taking place in the heart of Seoul A spine-chilling touching story. Every night from eleven to one. Jeoseung Restaurant is open now! The underworld restaurant is open now!