Pop trio Perfume will appear at Rock in Japan in what is likely to be the most thrilling spectacle of the weekend — while making the festival's name seem utterly inappropriate. Expect idiosyncratic dance routines, are-they-aren't-they miming debates, and a whole parkful of tech-tastic tunes as the idol band it's OK to be head over heels in love with hold court. Don't let the girls' chart-topping success fool you: Produced by Yasutaka Nakata of electro outfit Capsule, Perfume are cut from the same post-Shibuya-kei cloth as such underground kitsch cuties as Plus-Tech Squeeze Box and YMCK, offering an off-kilter dance sound that is not so much Kraftwerk as Kraftplay.

Also check out: Rock in Japan's all-Japanese lineup barely changes year on year, but look out for studio boffin Air, up 'n' coming indie band Jinn, postrock chicks Mass of the Fermenting Dregs, and regulars such as grunge revivalists HiGE, enka-styled rockers GO!GO!7188, guitar-pop starlet Yui and ska-loving party-starters Your Song is Good.

The setting: Arguably Japan's most easygoing festival, Rock in Japan dots its stages around a lush family park, offering great food, glorious sunshine and plenty of toilets. The punters tend to be young and trendy, although you'll spot a few families, and foreigners are an exotic rarity.

When/where: Aug. 1-3; doors open 10.30 a.m. Hitachi Seaside Park, Hitachi City, Ibaraki Prefecture. Tickets ¥10,500 per day or ¥30,000 for the weekend. www.rock-net.jp/fes/08