Back Number is a Japanese rock power trio formed in 2004. The group consists of Iyori Shimizu, Kazuya Kojima , and Hisashi Kurihara. The group signed to independent record label Idolsmith Recordings in 2009 and released their debut EP Nogashita Sakana and studio album Ato no Matsuri (2010). They signed to Universal Sigma in 2011. The group’s biggest hit is Christmas song, which peaked at number-one for three weeks on the Japan Hot 100 chart, and was later certified million by the Recording Industry Association of Japan. Their first compilation album, Encore, reached number one on the Billboard Japan Hot Album for two consecutive weeks in 2016 and also ranked number five on the Oricon yearly best-selling album chart of 2017. In 2018, back number successfully held a Dome Tour titled “stay with you”, including a 2-night-concert in Tokyo Dome. All tickets for 5 concerts are sold out within 2 hours, mobilized over 45,000 guests per concert.
In 2004, the band formed in the mind of Iyori Shimizu in Gunma prefecture. The band was named “back number” because of a girl who had dated Shimizu in high school, dated another bandman. To her, Shimizu is an ex-boyfriend, a “back number”. He wanted to make a “cooler” band than that guy’s band with a hope that the girl might come back to him. It took two years for the band to come to shape with other members (not the current members) in line. Then some disagreements were born and other members’ work priorities got in the way. The person who was in charge of the bass at that time wanted to quit and then joined Kazuya Kojima, who is a childhood friend of Shimizu and is now the current bassist. With Kojima joining, the band’s activities were continued but this time, it was the drummer who wanted to withdraw from the band. While looking for another drummer, Shimizu heard that the band of the guy who had taken his girlfriend had disbanded. Hisashi Kurihara, who was the drummer of that band and also went to the same high school as Kazuya, was recruited into back number and has been in charge of the drum since then. After that, the guitarist withdrew and the band was left with its current line-up till now. Then the group had a great big journey of experiences, new songs and concerts. Later, on June 2, 2010, released their first full-length album, Ato no Matsuri. Then on April 6, 2011, the band made their major debut with the single “Hanabira”. After two years,on September 7, 2013, the band held a one-man live “back number live at Nippon Budokan – stay with us-” at Nippon Budokan. From April 2014, the band was appointed as a regular personality of Nippon Broadcasting “All Night Nippon” on every Tuesday. On September 14, 2014, at the Yokohama Arena, the first arena performance “love stories tour 2014 – Yokohama love story 2 ~” was held. About one year later in December, 2015, their fifth album, Chandelier, reached first place on the Oricon chart for two consecutive weeks. On December 28, 2016, the band released their own all-time best album, Encore, which reached number one on the Billboard Japan Hot Album for two consecutive weeks.
Back Number is also active on some social media platforms which are YouTube, Instagram and Twitter. The YouTube channel of the group is Back Number . As for now, the channel has 903K subscribers, 32 uploaded videos and over 538 million total number of views. On Instagram their account is back_number_official and has over 94K followers. As for Twitter, Back Number joined and created their channel on this platform in May 2011. The channel is Back Number Staff and has more than 452K followers.