The Genius Who Descended Into the Darkness

S1 E1: In the Midori mahjong parlor, Nangou is trying to pay off his debts by playing mahjong but unfortunately, he's losing badly. Just as the situation turns sour, a stranger wanders in on their game. After sharing a few wise words, Nangou is able to survive. This marks the beginning of a legend that will shake the underworld.