Su Xiaoxiao, the bottom-ranking good-for-nothing of the sect, has weak spiritual roots, trails at the bottom in cultivation, and spends her days slacking off and eating, despised by everyone. Unbeknownst to anyone, in a rusty sword she casually picked up sleeps Xuantian, a down-and-out ancient sword spirit. The once mighty and cold supreme being of the three realms had fallen overnight and become trapped in mortal iron, originally waiting quietly for the peerless sword master to awaken, but instead bound to a laid-back junior sister who only wanted to slack off and eat peanuts. One person and one sword endlessly bicker and crack jokes in their daily lives; her alchemy blows up the furnace with mishaps galore, while he delivers cold-faced snarky remarks and helplessly covers for her. The good-for-nothing junior sister teams up with the ancient sword spirit to kick off a contrasting counterattack, a lightly healing path of cultivating immortality.