Eru was born as Jo Sung-hyun on July 5, 1983 in New York City, United States to Korean parents. He is the second and youngest son of one of the most popular and veteran Korean trot singer, Tae Jin-ah (né Jo Bang-hun).
Eru lived in New York until he was 7 years old, then his family moved to South Korea, where he attended numerous international schools including Seoul American High School. In 2003, Eru attended the prestigious Berklee College of Music (Piano Department) in Boston. Eru entered the K-Pop scene himself during a break from Berklee.
In late December 2007, Eru released a statement revealing his intentions of fulfilling his military service duties in the latter half of 2008, since he became a Korean citizen 2 years ago.
In May 1, 2008, Eru entered the boot camp to start his mandatory military service at Nonsan Military Training Center. Eru stayed there for four weeks to receive basic training and was subsequently assigned to public service duty. He completed his duty within two years, and returned home on May 27, 2010.
In addition to his singing activities, he was attending Dankook University.
Eru wanted to be a producer so he composed many songs. But after a while, he decided that he did not want other people to sing his songs. He wanted to sing them himself. He thought that the person who composes the songs understands them better. That's when he decided to become a singer.
Eru went through two years of training before making his debut as a singer in 2005. Eru's debut album included works from musicians such as Joo Young-hoon, Lee Hyun-jung (the composer of Big Mama's "Break Away"), and vocal trainer No Young Joo, who trained BoA, Fly to the Sky and Lee Soo-young. A 100-member string orchestra also participated in his debut album.
Eru debuted with released his first single from his 1st album was "다시 태어나도" ("Rebirth") on September 5, 2005. Eru released his 2nd album Level II on September 16, 2006. The first single from his 2nd album, "까만안경" ("Black Glasses") which features singer Daylight, gained significant popularity among young people and topped on- and offline charts. The song would later be showered with numerous awards, including Jukeon's song of the month (October 2006) and SBS's Bonsang Award. The music video for "까만안경" was also popular among his fans, as it featured Kim Hyun Joong of SS501, Lee Young Ah and Ahn Sung Ki.
After the huge success of "까만안경", Eru released his second single "흰눈" ("White Snow"), which he wrote himself. "흰눈" was also successful, reaching #1 on various online charts and winning several awards, including Cyworld's Song of the Month (January 2007). The music video for "흰눈" was shot in Sapporo, Japan and featured Eru and entertainer Lee Hyun-ji. Aside from his own music videos, Eru appeared in female singer Magolpi's debut music video "Flight Girl", where his role was as a composer, along with six other Korean artists, including Yoochun of TVXQ, Kangin, Heechul and Shindong of Super Junior, Park Joon-hyung of g.o.d, and Kim Jang-hoon.
In March 2007, Eru received an offer to appear in a Japanese movie titled Three Tattoos. Eru's agency stated that the offer was quite tempting, as the movie was being directed by Sukimori Hitomi and would likely be exported overseas. However, Eru's agency also stated that Eru would reject the offer as he has yet to establish himself in Korea as an artist.
Eru released his 3rd album Eru Returns on September 19, 2007 and it became the #1 album during October 2007, selling 42,228 copies in South Korea. The lead single from this album, "둘이라서" ("Because We Are Two"), enjoyed enormous popularity, winning SBS's Bonsang Award. The music video for this song featured celebrities Ahn Sung-ki, Bong Tae-gyu and Park Joong-hoon. Eru also released "겨울나기" ("Wintering") and "마네킹" ("Mannequin")" as singles from Eru Returns. The star-studded music video cast for "겨울나기" included Eru, actresses Lee So-yeon and Kim Ja-ok, actor Park Sang-myun, trot singers Tae Jin-ah and Song Dae-kwan, comedians Lee Kyung-kyu and Ji Sang-ryeol, singer Kim Heung-gook, and others.
His first solo concert took place on February 16, 2008 in South Korea.
Eru has released a music video titled "White Tears," his single for his fourth album. His fourth album was released on August 23, 2010.
In 2013, Eru collaborated with Indonesian comedian Sule in a multi-lingual music video titled "Saranghaeyo".2006: KBS Drama The Vineyard Man OST (Track 04. Good Lady)2007: KBS Drama Capital Scandal OST2008: SBS Drama First Wives' Club OST2009: KBS Drama Sons of Sol Pharmacy House OST2010: KBS Drama King of Baking, Kim Takgu OST2011: SBS Drama My Love By My Side (just one - part 6)2013: KBS Drama Secret OST