Original sentence: His first composed song was "Kizuna" last 2005 then "Special Happiness" last 2006 in which he sang with his co-member Taguchi Junnosuke and his latest written song which is sang in their BTR Summer Tour 2009 "Because I Love You"
Edited sentence: His first composed song was "Kizuna"  which was composed last 2005 then "Special Happiness" which was composed last 2006 in which he sang with his co-band member Taguchi Junnosuke and his latest written song which is now sang in their BTR Summer Concert Tour 2009 "Because I Love You"