Wanna One's Yoon Ji Sung is gifting his beloved fans with a surprise single, after enlisting as an active duty soldier some time today (May 14). 

On May 14 at 12 AM KST, Yoon Ji Sung shared a surprise farewell clip for his fans. He announced, "Would I really leave Bab-Al's (Yoon Ji Sung's fanclub name) alone? Instead, I will release a surprise single this May 19." 

Yoon Ji Sung's upcoming single "Winter Flower (冬,花)", a meaningful song looking back on the idol's up-and-down journey from his 'Produce 101' season 2 days to his debut with Wanna One, and now. The song is composed by musician Coffee Boy with lyrics written by Yoon Ji Sung himself. 

Look out for Yoon Ji Sung's "Winter Flower (冬,花)", coming on May19 at 6 PM.