Ai is the one who make the drug that shrunk Shinich
into a kid
.
She is also a vtctim of her drug and she also turn into kid.
She is like Shinichi. Her real name is Shiho Miyano. She was the one who invented
the drug that shrunk Shinichi and herself. Her codename was Sherry, but the
death of her older sister made her turn away from the Underground Crime Ring.
When the Underground decided to kill her, they handcuffed her to a pipe on the
wall to await her execution. Since they were going to kill her, she took her
own drug, intent on killing herself first. Instead, she was shrunk, and her
hand was able to slip out of the handcuffs.