사랑인가봐 (월수금화목토)

The definitive Korean drama love theme of the 2020s, and it earns that by being almost aggressively unembarrassed. MeloMance build it on Jung Dong-hwan's piano — bright, rolling, major-key, closer to a show tune than a ballad — before strings and a full band arrive to lift the second chorus into open sky. Kim Min-seok's voice is the hook: clear, slightly nasal, boyish in a way that reads as sincerity rather than youth, and he sings the title phrase ("I think it's love") with a small upward catch, like someone realizing something mid-sentence. There's no ache here, no minor-key hedging — it's the rare Korean OST about the giddy, disbelieving front end of falling, not the wreckage after. The lyric keeps circling the same discovery: ordinary days have started rearranging themselves around one person. Written for *Business Proposal*, a rom-com built on mistaken identity and workplace farce, the song became bigger than the show, dominating domestic charts for months and turning into a wedding and karaoke standard. It's morning music, commute music, the thing playing while you text someone you've just started seeing — full sun, no shadows, and completely unbothered by how uncool that is.