Mama Mahjong

On the day their two sons left for an overnight study, Naoko and Youko held a dinner party at the Hobara household to relax and have some fun together.

A woman came to the party, Rie Funaoka, a junior colleague of Naoko from her days as an office worker.

The party is a charming and enjoyable one, the drinks are flowing and before they know it, they are discussing the possibility of playing mahjong. To make up for the lack of players, Rie's brother-in-law, Tadashi, was summoned with a single phone call.

Youko comes up with a killer idea to inspire Tadashi who is a ronin, and the idea is stripe mahjong!

[From official site]