Detective Conan Lee, who is the short-haired woman?

It is found that the short-haired girl in Luyuan is Sera Masumi, a transfer student in Dan High School and a classmate of Zi Yuan and Xiaolan. The episode of reasoning confrontation that first appeared in the ghost hotel. She is a female detective who is good at Jeet Kune Do. She has extraordinary skills and excellent reasoning ability. Her chest is so flat that she will be considered a man if she doesn't wear a ring. I am interested in the identities of Conan and Zuyuan. It seems that I already know Conan's true identity. From the appearance, she is Akai Shuuichi's sister.

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