The new song was put up on BTS' official social media for free download, along with a music video.
V, whose real name is Kim Tae-hyung, composed the song with producers of his agency Big Hit Entertainment and wrote the lyrics for the new release.
It is V's first English-written song following his first self-created Korean song, "Scenery," in Jan.
RM, the leader of the septet, helped translate the lyrics into English, according to BTS' Twitter.
"I'm the one who wrote English lyrics for the first time," V tweeted. "I wrote the lyrics while watching a movie during a tour. Thank you, RM for your help."
Starting with an acoustic guitar melody, "Winter Bear" conveys lyrical warmth through V's low voice, featuring a hibernating bear in the winter.
BTS members each have released self-made digital solo songs one by one. Team leader RM released a package of his own songs, "mono.," in Oct. last year, followed by Jimin, who unveiled the self-composed single "Promise" in Dec. (Yonhap)