Sehun and Krystal are dating, and nothing's standing in their way. Except for the fact that Krystal's older sister, Jessica, has feelings for the younger male. And on the other side, Krystal's best friend, Jiyoung, has a crush on Krystal.

Krystal Jung:

A girl who looks like she can kill with a stare, but she has aegyo for miles. She's currently dating Oh Sehun, her college crush and she's too happy for words. Although, she senses something different with her sister, Jessica, ever since she's dated Sehun and she doesn't know what. She trusts her best friend, Jiyoung, with everything.

Jessica Jung: 

Similar to her younger sister, she has embodiment of an ice princess. But on the inside, she has a warm heart. Ever since Krystal introduced Jessica to Sehun, she's developed a bad crush on him. She doesn't know why she has the feelings, and they won't go away. Her best friends are Taeyeon and Yoona.

Oh Sehun:

A young man who doesn't look like he cares about anything, because of his stoic outside. But he cares deeply for his girlfriend, Krystal. When he sees her sister, something inside him doesn't feel right. But he shrugs it off like it's nothing. His closet friends are Baekhyun and Chen.

Kang Jiyoung:

A loyal person to her friends, she is honest about everything. Well, almost everything. She's had a secret crush on her best friend Krystal since they were young. She quietly wishes they could be together. But she just wants Krystal to be happy, even if it means breaking her own heart. She often talks about it with her good friend, Hara.

Other Characters:

Taeyeon and Yoona: Childhood friends with Jessica

Baekhyun and Chen: Best friends of Sehun

Hara: Close friends with Jiyoung