Filian has a lifelong friend. Nothing weird, just a best friend she's known all her life-- though Rosa is everything BUT normal. She shouts mathematical equations at her between bites of lunch, she moans the lack of something called a kalk-u-later, and she utterly hates even the merest mention of the country's prestigious Academy. Oh, and the air always seems to sparkle when she laughs.

And then suddenly a local duke waltzes in and claims her as his illegitimate daughter, and Rosa doesn't even bat an eyelash. Then she's enrolled into the Academy, and she's suddenly all jittery and afraid. Then she starts talking about probabilities? Plans? Routes? Secret targets?

Filian the commoner is as lost as she could ever be, and it's not going to get better anytime soon. Oh boy.

A light-hearted, comedic take on the isekai genre! :) Hope you enjoy!