Transmigrated: The Steamed-Bun Maid Has an Older Sister

Transmigrating? That's perfectly normal. Just think of it as winning a one-way travel ticket in a supermarket scratch-card raffle. And it's free, too! Transmigrating into the body of a kid? Fine. By the usual classifications, this is a soul transmigration. Wearing rags and lying in a cave in the middle of winter? Well, judging by the usual transmigration tropes, this must be the beginning of a farming story? But, damn it, Transmigration Bureau, you'd better explain yourself! Who opens their eyes after transmigrating and finds themselves face-to-face with their own "corpse"? Oh, my "corpse" is still alive... !!! Damn it! I'm inside this kid's body! So who's inside my body? This is the story of a nine-year-old body with the mind of a seventeen-year-old, aka a child prodigy, and a seventeen-year-old body with the mind of a nine-year-old, aka an idiot, embarking on a series of ridiculous adventures in an ancient world. The story starts slowly, and the male lead won't show up for quite a while ^-^ Don't mistake this for a girls' love story. The two girls are completely innocent! I swear on my reputation!