The series connecting monthly theme songs across 16 units from 315 Production's flagship program "P@SSION CHALLENGE We are 315!" is now available! The 8th entry features C.FIRST! Includes a new unit track as well as solo versions for each idol! As a bonus, a flyer with a serial code to unlock a CD bonus story viewable on the "315 PASSION CONTENTS" page within THE IDOLM@STER Portal SideM brand page is enclosed. Features a newly drawn illustration jacket.