Nashiko Jippensha, a high school student in Onomichi, is kicked out by her mother. When she has nowhere else to go, her father offers her his old mahjong club. With her friends, Pai Kawahigashi and Izumi Tokutomi, Nashiko begins renovating the club.

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

Now that the four friends have gotten the stove working, the next step is to prepare a meal. They decide to make a tasty curry with sashimi and water ice for dessert. But before that, they tidy up the old mahjong club.

Riche shows the other girls how to play mahjong online, against other players. Their opponents are strong, and Nashiko is unable to win. Fortunately, Riche is there to avenge her, and focuses on countering the strategy of an opponent.

Nashiko and her friends are visited by the person they were playing against online, Haneru Emi. She is determined to challenge Riche again to defeat her, but before that, she meets the four girls.

Nashiko and her friends make the most of their summer holiday. To celebrate Pai's birthday, they decide to spend the day at the beach with cake, gifts, and games. However, Pai feels embarrassed by Riche's gift.