Gundou Sensei, Sore Ron desu!

Popular VTuber Mirei Gundo is trying to run a mahjong parlor with the help of Osamu Saitou, a handsome character she summoned from a mahjong game, as her partner. If she can't revive the fortunes of the old mahjong parlor, Osamu Saitou will disappear! Can Mirei, a mahjong novice, manage her customers and make her mahjong parlor popular?

(Source: Takeshobo, translated)