There can't be an awkward time for me to be your older brother.

Yoon Yeo-ju, class 3, freshman at Pledis High School. Thanks to her older brother, Yoon Jeong-han, she knows many older brothers, but her shy personality makes it difficult for her to adapt. She's known all of Jeong-han's friends for at least five years, but her relationship with Lee Ji-hoon, his best friend of ten years, is awkward for some reason. The day Yeo-ju first meets Ji-hoon after entering high school, Ji-hoon sees Yeo-ju smiling brightly like a green apple, and from that day on, he has