For volume 9 of the Idolmaster Gravure 4 You! series, the idols are all dressed up in yukatas -- perfect timing, as this latest anime/game hybrid comes out just before the start of the fireworks season.

This latest entry also includes "sailor bikini" costumes. I've attended many a fireworks celebration, or "hanabi" as the Japanese call it, and never once saw girls in sailor bikinis, so I'm going assume the yukata and bikini outfits are unrelated.

Gravure 4 You! vol.9 arrives on June 28, priced ¥9,980. As producers might have figured out from the screenshots, the collection also includes idol Ryo Akizuki, meaning the gravure series now has all the girls from Idolmaster Dearly Stars.