reason!! (idolmaster)

The opening theme to the anime adaptation of THE IDOLM@STER: SideM. Sung by the focus groups of the anime, Dramatic Stars, Jupiter, Beit, S.E.M, High X Joker, and W.

The outfit worn during the sequence is an idol costume; a red & jacket with epaulettes and folded short sleeves, a blue vest with a black necktie underneath, and black pants.