Yeah there's gonna be a running theme of isekai stories going on here, sue me.
Once a pushover in iur world, the MC is sent by truck-kun to a new world to inhabit the body of a spoiled, vicious Duke's daughter-- Debora Seymour. Instead of trying to sell a 180 personality change in the Lady, the MC takes this opportunity to learn how to assert herself and set boundaries, all while carefully crafting a plan to not be doomed to the same bad end as the original Debora in the novel.
So we got a sweet mouse MC pretending to be a wolf-like lady, a plan involving a charismatic mage, capitalism as a tool for independence, magical mathematics, and a pretty sweet story pace. Found on Tapas, I highly recommend it!