Just get your girlfriend to cosplay and talk like her, win-win cooperation as the Chinese like to say.Furudo Erika from Umineko No Naku Koro Ni.
I have like, a massive crush on her lol. So much that it makes my actual girlfriend jealous sometimes lol
She's a super obsessive "detective" character, and her whole persona is based around ripping open mysteries and exposing the insides. As an analyst by trade, I can't help but feel endeared to her on that alone.
Also, Umineko is my absolute favorite fictional work of all time. Highly recommend you read the Visual Novel (the Anime sucks super bad)