Kasumi, alongside her sisters Miki and Shouko, finds herself abruptly displaced into an alternate dimension. Within this realm, mahjong tiles serve as the fundamental currency. No explanation or context for their arrival is provided. To return home, the sisters must achieve a singular objective: defeat the dimension's ruler, a rabbit who governs through mahjong challenges. Their entire journey focuses on this necessary confrontation. Kasumi participates solely as part of this collective effort to win the pivotal mahjong game against the rabbit ruler. No details exist about her individual personality, appearance, history, specific mahjong skills, relationships with her sisters beyond their shared goal, or personal growth during the quest. Official media beyond the original 1990 OVA narrative provides no further background, character development, or experiences for Kasumi.