Robot sequence of Idolmaster 15th episode was apparently done by 'STUDIO TRIGGER', which is a NEW STUDIO created by Imaishi Hiroyuki, Ootsuka Mashiko and other members of Gainax. To be more specific, it's studio made by staffs of Tengen Toppa Gurren Lagann and Penty & Stocking. Not just that, they are also in charge of Idolmaster 17th episode. Not just some sequences, but ENTIRE EPISODE will be directed by them. When I can't watch it due to well known shitty reasons (;_;), it would be so awesome to see it.
CEO: Ootsuka Mashiko
Company Director: Imaishi Hiroyuki
Company Director: Masumoto Kazuya
*Idolm@ster ep. 17
Conti (Storyboard), Direction: Shibata Yuka (This guy draw entire OP sequence of Penguindrum. Crazy.)
Animation Director: Sushio (Ishijaki Toshio)
They are all members who participated in TTGL.
Gainax may be dead from now on, but their successors will never die. Everyone, remember 'STUDIO TRIGGER'. They might do something crazy again!
*Episode 17 Preview + Key drawings etc