Two boys are desperately in love on a spring day. Eighteen year old Baek is diagnosed with Cardiac Arrhythmia, while Chan is in last stage of lungs cancer. The two never speak to each other, even though they both go to the same all boys school. Until fate and destiny lead them to the school rooftop, and they become friends. Against all odds that were thrown at them, they strengthen their love while making unforgettable memories.