Pil Seo-jin or Bi Shu-jin (Chinese: 畢書盡; pinyin: Bì Shūjìn; Korean: 필서진; romaja: Pil Seojin; born July 7, 1989), known professionally as Bii, is a South Korean-born Taiwanese singer, songwriter, and actor.

His life in South Korea was reported to be a bit challenging as he did not qualify for a national identity card.

At the age of 17, SM talent agent scouted Bii, who was a high school student then, but his mother rejected the idea of him being a singer.

[4] [5] His songs have been featured in many TV series, such as Zhong Wu Yan (2010), Love Around, Someone Like You, Bromance, Prince of Wolf, and Better Man in Taiwan.

He appeared in Episode 1 of the TV series Someone Like You (2015) as Gu Long, who raced against Fang Zan Cheng played by Kingone Wang.