Yoon Hana is suddenly forced to leave her beloved neighborhood and must move to a different town. Instead of being enrolled at her high school she was supposed to be in, she got enrolled to Youngsol High. And with that Hana anticipate her new start. However, she ends up being an outsider on the first day of transfer and even ran into a scary male student…! She worries if she'll be able to have peaceful daily life, yet… "I'll help you make 100 friends!!" The open-hearted Hana ends up making a completely nonsensical promise to Chang-wook, who has a different side to him unlike from the rumors surrounding him. This is the sunny-like Hana and gloomy, but beautiful Chang-wooks's project to make friends!