Conversation so far:
when did onizawa depart from one ok rock?
In May 2009, it was announced that One Ok Rock would continue on without Alex, who went back to the United States.
why did he go back to the US?
CANNOTANSWER.
who took his place?
Toru took his place as lead guitar, and the band re-arranged their songs to be played for one guitar.

Question: what's another release from 2007-2009?
Self-contained rewrite: what's another release by One Ok Rock from 2007-2009?