The brother and sister who decide everything through the King's Game: Kururugi Aoi (MIAE-340)

In my family, we always decide things by playing King's Game. It's the same for everything: how to divide snacks, who gets to bathe first, whether to keep a cat or a dog. The older brother, if he wins, lets his sister lick the stick, but she'll secretly become his "assistant gun" along the way. This game of cat and mouse plays out every day.