、KODAI、T-MAX、SJ于2014年底组成的、以R&B和Hiphop为主打曲风的四人组合，2015年开始四人活动。后成员SJ因个人原因退出X4 ，于2016年2月22日加入新成员SHOTA、JUKIYA，成为五人组合进行活动

生日：1990年05月24日星座：双子座身高：180cm体重：60kg血型：A型出生地：日本 兵库县（Hyogo）

所属公司：Epic Records Japan(2008 - 2012) Japanese Dream Records(2013 - )事务所 CALESS Co. Ltd.偶像：Michael Jackson、Kanye West、JAY-Z、John Legend、 Pharrell Williams、/N*E*R*D

生日：1992年05月02日身高：176cm体重：64kg血型：AB型

出生地：日本 大阪（Osaka）前组合：BOYCE前名：KID

姓名：松本拓马生日：1991年07月08日血型：O 型出生地：日本 京都（Kyoto）

前组合：EDEN前名：TAKUMA兴趣：筋トレ、旅行、食べ歩き、ネットで服见る偶像：chris brown、omarion 、usher、BIGBANG、NEWBOY喜欢的电影：シックスセンス(灵异第六感)喜欢的品牌：GIVENCHY、BALMAIN

姓名：平良翔太平假名：たいら　しょうた生日：1996 年 05月04 日血型： B型出生地：日本 冲绳（Okinawa）特长：室内足球和台球个人经历：人气模特SHOTA TAIRA，也在niconico动画上作为唱见活跃。在东京ボーイズコレクション中获得第三位的好成绩，爱称为「翔にぃ」。

姓名：采本树辉也生日：1999 年11月18日血型： O型出生地：日本 大阪（Osaka）

★2nd SINGLE「Party Up!!」2016.03.30 Release

1：Party Up!!2：誓い3：IDKYN（I don’t know your name）

★Debut Single「Killing Me」2015.10.7 Release

1：Killing Me2：MONSTER3：#musicoverdose -X4 ver.-

★4 Digital Single 「IDKYN（I don’t know your name）」2016.2.24 Release

★3 Digital Single 「obsession」2016.1.27 Release

★2 Digital Single 「Snow Flakes」2015.11.26 Release

★1 Digital Single「声にしたなら」2015.6.13 Release

★ 1st ALBUM「Funk,Dunk,Punk」2016.5.25 Release

M1 : Funk,Dunk,Punk　（新曲）Lyrics by X4　Music by X4 　Arranged by X4M2 : Party Up!!　*2nd SINGLELyrics by X4　Music by X4 / RUSH EYE　Arranged by RUSH EYEM3 : Dive into your love　（新曲）Lyrics by U　Music by 小田桐ゆうき　Arrange by 小田桐ゆうきM4 : Killing Me　*1st SINGLELyrics by SJ / H.U.B.　Music by B.Thompson/Lazy-Q　Arranged by Lazy-QM5 : obsession　*Digital SINGLELyrics by　U　Music by　V10　Arranged by V10M6 : You　（新曲）Lyrics by FUNK UCHINO　Music by Carlos K., FUNK UCHINO　Arranged by Carlos K.,M7: Rainbow Road　（新曲）Lyrics by U　Music by Jin Nakamura　Arranged by Jin NakamuraM8 : 声にしたなら　*Digital SINGLELyrics by KENGO / KODAI　Music by Route A / KENGO　Arrangerd by Route AM9 : Snow Flakes 　*Digital SINGLELyrics by U /小田桐ゆうき　Music by 小田桐ゆうき　Arranged by 小田桐ゆうきM10 :IDKYN（I don’t know your name）　*Digital SINGLELyrics by U　Music by B.Thompson / Lazy-Q / TONKATZ　Arranged by Lazy-QM11 : 薬指　（新曲）Lyrics by 须藤 哲平　Music by 须藤 哲平 / サイトウリョースケ　Arranged by サイトウリョースケM12 : 誓い　*2nd SINGLE c/wLyrics by PA-NON　Music by 多田慎也　Arranged by 中村佳纪M13 : DISTANCE　（新曲）Lyrics by SigN　Music by SigN　Arranged by SigNM14：#musicoverdose –X4 ver.-　*1st SINGLE　c/wLyrics by U 　Music by U / Route A　Arranged by Route AM15 : LOVE COST　（新曲）Lyrics by 佐伯公介　Music by 佐伯公介　Arranged by SigN / NeckyM16 : Fly in　（新曲）　*ボーナストラックLyrics by KODAI　Music by KODAI / Route A　Arranged by Route AM17 : 欲望　（新曲）　*ボーナストラックLyrics by 须藤 哲平　Music by 须藤 哲平/ SigN / Necky　Arrange by SigN / Necky

★ 1st Digital Album「XVISION」2015.2.22 Release

1 THEME OF XVISIONMUSIC BY Route A / ULYRICS BY UARRANGED BY Route A2 FIREMUSIC BY Carlos K. / SuzanLYRICS BY UARRANGED BY Carlos K.Additinal Guiter by TAKAYUKI SASAKI3 Bang A GongMUSIC BY TAKATSUGU TSUMABUKILYRICS BY KOUDAIARRANGED BY TAKATSUGU TSUMABUKI4 Future,Super Duper,NovaMUSIC BY Route A / ULYRICS BY UARRANGED BY Route A5 最后の言叶MUSIC BY Hiroki Sagawa / Carlos K.LYRICS BY H.U.B.ARRANGED BY Carlos K.Additinal Guiter by TAKAYUKI SASAKI6 三日月MUSIC BY SigN / Lazy-QLYRICS BY タケヨシキ / Lazy-QARRANGED BY SigN / Lazy-Q7 RaindropMUSIC BY B.Thompson / Lazy-QLYRICS BY H.U.B.ARRANGED BY Lazy-Q8 Little LongerMUSIC BY B.Thompson / Lazy-QLYRICS BY CAMELARRANGED BY Lazy-QAdditinal Guiter by TAKAYUKI SASAKI,Strings by Tsubasa Ito, Flute by Yoshihiro Okazaki(Itcha)9 HeavenMUSIC BY B.Thompson / Lazy-QLYRICS BY UARRANGED BY Lazy-QAdditinal Drums by くわG,Guiter by Hajime Wada10 I Don't Know Your NameMUSIC BY B.Thompson / Lazy-Q / TONKATZLYRICS BY UARRANGED BY Lazy-Q / TONKATZAdditional Guiter by SUBARU11 LOST GAMEMUSIC BY SigNLYRICS BY kenko-pARRANGED BY SigNALL SONGS PRODUCED BY YUYA

1st TOUR【X4 LIVE TOUR 2015 –XVISION-】2015.3.20~4.29

【X4 LIVE TOUR 2015 ～Killing Me～】2015.10.21~

「X4 LIVE TOUR 2016 -Party Up!!- 」 2016.4.1~5.26

<X4 LIVE TOUR 2016 -Funk,Dunk,Punk→ 2016.7.2~8.26

舞台剧『私のホストちゃん THE FINAL ～激突。名古屋栄编～』（2016年）

舞台剧『私のホストちゃん THE FINAL ～激突。名古屋栄编～』（2016年）