Nashiko Jippensha, a high school student living in Onomichi, is kicked out by her mother; with nowhere else to go, her father offers her the use of an old mahjong club he once ran, now long abandoned.

Riche meets up with Nashiko at the mahjong club, just as she promised, and manages to convince her to let her join their group of friends; she also gets to know Pai, Izumi and Chombo, and around the mahjong table, a new friendship begins to form.

Now that the four friends have gotten the stove working, the next step is to prepare a meal; on the menu, a curry with sashimi and a water ice for dessert; before that, they start tidying up the old mahjong club.

Riche shows the other girls a new way to play mahjong, online, against other players; the opponents the three beginners face are strong, and Nashiko seems unable to win; fortunately, Riche is there to avenge her.

Nashiko and her friends receive a visit from the person they were playing against online, her name is Haneru Emi; she's determined to challenge Riche again to defeat her, but before that, she meets the four girls.

The mahjong enthusiasts organize an overnight stay at an inn in Onomichi to play mahjong; they also take the opportunity to visit the city's tourist spots that they don't normally get to see.