"Am I an adult? Or am I a kid?" sings Kyary Pamyu Pamyu on "Furisodation," a song about the Harajuku blogger-turned-model-turned-pop-star turning 20 earlier this year. That's the question that looms over all of her sophomore album, "Nanda Collection."

The album is obsessed with the messy transition from youth to adulthood, the sound of Kyary figuring out Kyary. At times she's a ninja, a monster, an invader and a lush. "Nanda Collection," though, is consistently compelling, the year's finest coming-of-age document and 2013's best pop album so far.

It helps that producer Yasutaka Nakata still sounds like he's having fun experimenting with the music. Like last year's great "Pamyu Pamyu Revolution," Nakata stuffs "Nanda Collection" with catchy hooks and a love of individual sounds (the syllable "mi" on the taiko-rhythm-game-meets-Eurodance of "Mi," or "nori" in "Noriko to Norio"). Yet now, he's unafraid to let his productions sound confrontational. "Ninja Ri Bang Bang" features the sound of swords being drawn, slicing through an otherwise jubilant tune, while "Invader Invader" includes bass-heavy interludes reminiscent of dubstep/EDM artists like Skrillex.