Doyoung of NCT is sharing a warm thank-you through his new single Promise.

The singer releases Promise at 6 p.m. on December 9 across major music platforms, accompanied by the music video for the title track Late Words (Promise).

Two-Track Single Filled with Emotion

The single includes two songs: Late Words (Promise) and Whistle, featuring Bell of Kiss of Life. Both tracks carry expressions of gratitude toward fans.

Late Words (Promise) is a ballad that begins with a minimal piano line and gradually expands with strings, deepening its emotional impact. Doyoung wrote the lyrics himself, delivering an intimate confession to "my precious love." Even if spoken late, the message resonates deeply.

The music video uses a clover plant as a motif representing Doyoung and his fans — a tender reminder of connection despite physical distance.

Whistle is an R&B ballad capturing the moment two hearts communicate through a soft whistle. Doyoung and Bell's vocals interlace like a gentle conversation.

Fans can also purchase the Promise single in physical album format starting the same day.