Pachislo Kizoku Gin (Series)

Ginya Otonashi is a college dropout who works part-time for a pachislot publishing company while aspiring to become a novelist. One day, Ginya comes across a secret organization and gets pulled into a competition to become #1 in "Pachi Battle," which is all a part of the Slotseum, a pachislot competition. (Source: ANN)