Riche defeated a strong opponent she met in an online mahjong game. While they were in a celebratory mood, their opponent in question, Emi Haneru, arrives. Immediately upon arriving, Nashiko is initially impressed to see her requesting a rematch with Riche. However, after hearing the words of Riche and her friends, she is inspired. Later, to deepen their friendship with the girl, the group begins a certain strategy...