After countless days and nights of anticipation and tireless effort, Ai Haibara finally succeeded in synthesizing the antidote. When Conan and Ai Haibara took the miraculous medicine, their bodies returned to their adult forms. But happiness always comes with challenges. After returning to normal, Conan often fell into brief episodes of neurosis. His mood would swing between highs and lows, and he would occasionally lose his memory. Ai Haibara, on the other hand, suffered far milder side effects. So Yukiko Kudo decided to take Conan to New York for treatment.
Six months later, Ai Haibara, seeking to evade the Black Organization's pursuit while continuing her research into the drug's side effects, came to New York as well. Yukiko Kudo had forged a doctor's identity for her. Given their circumstances and needs, they decided to live together in New York.
In New York, Conan gradually adjusted to his new identity. He still loved detective work and often helped the New York police commissioner solve all kinds of difficult cases. Ai Haibara, meanwhile, reluctantly joined in as his assistant.
After reading a few cases, I spent more time writing on them, and they were indeed well written. But from the few chapters I've read, there are relatively few interactions with Ke Ai. It's more like the real Sherlock Holmes and Watson story, decoupled from the characters in the Conan world.