[The premise will most likely change. In any case, this is an upgrade-focused xianxia story.]
Yu Chuxia transmigrates into a xianxia mobile game. Because she skipped the tutorial, which could have brought her to level 10, she becomes the only level 0 character in the game.
The lowest-level monsters in this world are level 3, the first dungeon requires level 10, and even Granny Wang, who sells melons by the roadside, is level 1. Yu Chuxia is level 0. She punches a level 3 monster, but it kicks away most of her health bar in return, nearly killing her on the spot.
Homesteads unlock at level 30; sects unlock at level 40. She can't kill monsters, and without spirit stones she can't afford an inn... To avoid sleeping on the street, Yu Chuxia has no choice but to start out as a maid, serving the young master of a wealthy household.
Other NPCs have to cultivate diligently to level up, but Yu Chuxia is a real player. She can level up by eating, by fighting monsters, and even by soaking in a spirit spring... Her smile slowly turns wicked. So this is the difference between players and NPCs!
With the help of her player cheats, she takes the path of the phoenix-turned-heroine's comeback and face-slapping. There's just one thing she can't figure out: no matter how many levels she gains, that young master is always three levels ahead of her.
At first, she doesn't know why. Then, on the night she and the young master become cultivation partners, she lies in his arms and suddenly realizes: the ultimate boss being three levels above the player is a scummy pay-to-win mobile game's standard trick.
Yu Chuxia stares at the man. Oh?
Mu Wanqiu curls his lips. "Wife, would you like to do that again?"
*One-on-one pairing, both leads are each other's only partners, happy ending, no children.
*They really enter a game, with no forced plot.
*Long-form level-up story, with romance and plot progressing in parallel.
*Though it's obvious, I'll note that the title was inspired by the Japanese anime Re:Zero - Starting Life in Another World.
Theme: Always strive to improve