"Call / I4U" s the 29th single by Japanese pop group AAA. It is included in the group's second best of albumAAA Best. The song was written by Kenn Kato and Mitsuhiro Hidaka. The single was released in Japan on August 31, 2011, under Avex Trax in six editions: CD and DVD A and B editions, CD-only C and D editions, and two Mu-Mo editions. "Call / I4U" debuted at number five on the weekly Oricon singles chart. The single charted for nine weeks and went on to sell over 42,300 copies in Japan.
"Call" was written by Kenn Kato and Mitsuhiro Hidaka, composed by Masanori Takumi, and arranged by ats. "I4U" was written by Yusuke Toriumi and Hidaka, composed by Jam9 and ArmySlick, and arranged by ArmySlick. "Crazy Gonna Crazy (2011 Ver.)"—originally by TRF—was written and composed by Tetsuya Komuro, and arranged by Tohru Watanabe.
"Call / I4U" was released on May 16, 2012, in four editions: a CD and DVD A edition, which includes the music video for the song and the first part of the music video making; a CD and DVD B edition, which includes the second part of the music video making and an E~Panda?! video; a CD-only C edition, which includes "Crazy Gonna Crazy (2011 Ver.)" and its instrumental; a CD-only D edition; two Mu-Mo editions, which include the Think About AAA 6th Anniversary clips from seasons 10 and 11 in editions A and B, respectively. "Call" was used in television advertisements for hypermarketIto-Yokado's brand Body Heater; "I4U" was used as the theme song in the anime film Prince of Tennis: Castle Battle the British.