Plot

Depicts the solid friendship and sincere love story of 18-year-old youths who cannot give up love or friendship. The drama deals with the unique subject of cellular memory, which hypothesizes that memory is transferred to organ recipients.

Go Yoo ( Sehun) is an 18-year-old high school student. He has nothing in the world that he is scared about and he has many things he loves. He is excellent in playing basketball. His friend Go Joon-Hee (Jo Joon-Young) attends the same high school. Go Joon-Hee's academic score is always at the top of his school. He is physically weak and he had a kidney transplant from Go Yoo. Since then, Go Joon-Hee suffers from cellular memory syndrome (memories transferred through cells from an organ transplant). Go Yoo and Go Joon-Hee then fall in love with a transfer student Han So-Yeon (Jang Yeo-Bin) at the same time. Han So-Yeon is pretty and smart, but she has a secret that causes her to keep a distance from others.—AsianWiki

Go Yoo (Sehun) and Go Joon Hee (Jo Joon Young) are best friends - and polar opposites. While Go You is a basketball ace and an all-around athletic type, Go Joon Hee is quiet and bookish, with poor eyesight and many other ailments. Regardless, these two 18-year-old classmates are best pals. So when Go Joon Hee is in his hour of need, Go Yoo comes to his rescue, donating a kidney to his friend. But one day, while they are clowning around in the school medical bay, a female transfer student they have never seen before - named Han So Yeon (Jang Yeo Bin) - barges in to tell them to keep the noise down. The two friends are smitten with her at first sight - even though they have always had very different tastes in girls. As they get to know her, they both strike up a friendship with Han So Yeon. The two boys begin to wonder if cellular memory could be causing both of them to fall for Han So Yeon. And they soon begin to understand that she may be harboring a secret that she doesn't want to share with anyone.—Rakuten Viki