Affair 

Affair is a collection of short stories from a manga-ka whose men ooze testosterone. Shiuko Kano has never been shy about portraying real adult relationships and while Affair is a bit more subtle than her usual fare, it is by no means an exception. Two high school friends reunite; two yakuza sons find they have more in common than shady business dealings; and the stakes get raised in a mahjong game after work.