On that dazzlingly bright day, I saw you — someone even more radiant than the sunlight itself. Kang Yeon-woo had a younger brother, Yoon-hyuk, though they weren’t related by blood. Yeon-woo secretly cherished Hyuk in his heart, but that overly sweet emotion slowly began to consume him, and eventually, the two parted ways. Five years later, they meet again by chance. However, Hyuk still harbors resentment toward his older brother who disappeared without a word, and between them lingers a quiet, unspoken tension filled with unresolved feelings. What really happened between Yeon-woo and Hyuk?