Your friend, Keira has a heart disease. She's going to America for an operation. But before she went off, she told you to research about a guy named 'Kim Mingyu'. You eventually found Mingyu and his friend Dokyeom who's known as DK.

They're both part of the soccer varsity team with DK as the team captain

A few days after Keira left, you, Mingyu and DK became closer. One day, you, Mingyu and DK were eating in an Icecream store near your house when suddenly, the door opened and it's Keira.