I'm Still on the Road to Breaking Up [Crossover]

My name is Chisaki Rokujou. I have a twin brother, Chikage Rokujou, who claims to be a feminist. Looking at all my current, future, and ex-sisters-in-law, I swear I'll never turn out like my brother. I'll have only one boyfriend my entire life, then get married and stay faithful till death. Then, in my second year of university, I suddenly found myself in a romantic mess I didn't even know existed. One after another, people I barely knew, or didn't know at all, came looking for me and claimed to be my lovers. Every one of them had perfectly imagined our entire relationship, from our first meeting to when we started dating, and had even invented all sorts of details about me. I knew nothing about any of it. If I weren't actually broke, and if these people weren't so sincere, I'd have thought I was being set up for a honey trap. After investigating and sounding them out, I realized this wasn't a romantic mess at all. It was a mystery! Dear brother, this curse of blood ties really is hard to break! Next life, I don't want to be your sister! Things to note: 1. This isn't a story where everyone loves the heroine. She's an impressive ordinary person, not some unstoppable force. She's good-tempered and doesn't cause trouble, just a little mischievous, and somewhat of a flirt when it comes to romance. 2. Also known as “Detective Chisaki.” 3. There are lots of obscure anime and characters, but they're mostly unrelated to the original plots, so it won't affect your reading. Usually updated daily. 4. The chocolate premise comes from the Tencent Comics series “Cupid's Chocolates,” with some fan-created details. 5. The pairing is already decided: Dazai from Bungo Stray Dogs. Theme: