Twinkle, Twinkle, Little Star

Crystal Birchwood, the granddaughter of the richest Zachary Birchwood, and Stella Johnson, the daughter of the ordinary Johnson family, were accidentally switched when they were young. Twenty years later, Stella Johnson (formerly Crystal Birchwood) who grew up in an environment where the Johnson family highly values boys over girls was harassed by her younger brother, while Crystal Birchwood (formerly Stella Johnson) lived a life of luxury in the Birchwood family. The two were admitted to the same university. Crystal bullied Stella because the boy she liked was pursuing Stella. The teacher who was unexpectedly called by Stella‘s friend to rescue Stella was Stella’s ex-boyfriend Grayson Birchwood. They met by chance in a convenience store. Stella was touched by Grayson's gentlemanliness and care, they had sex after drinking, and since Stella was rescued by Grayson, they maintained a bed-mate relationship for a year but broke up due to a misunderstanding. After Grayson scolded Crystal, he couldn't help but care about Stella, but his kindness was not accepted. When Stella was called by Grayson to explain the bullying incident, she learned that he was her new teacher.