In a world where Skill Fruits grant powers, aspiring adventurer Light is stuck with the useless «Fruitmaster» skill. Eating another one results in death, so no do-overs. Meanwhile, his childhood friend Rena quickly rises to S Rank. But when Light accidentally eats a second Skill Fruit, he survives and discovers his true power: He can consume unlimited Skill Fruits and gain their abilities!

The story is set in Hiroshima Prefecture's Onomichi City, where a high school student Nashiko Jippensha was kicked out of her house. Without a place to play with her friends, she learns that the mahjong parlor that her father used to run is now vacant. She fixes the mahjong parlor and turns it into a place where she and her friends can have fun, cook, have tea, and sometimes play mahjong.