The J-pop world could use a few more artists like Chanmina. In the leap from high-school MC battles to the commercial mainstream, she has managed to hone her pop appeal without sacrificing her swagger. Anyone who calls their debut single "Fxxker" isn't trying to make fans the old-fashioned way.

On sophomore album "Never Grow Up," the 20-year-old continues to pivot between outlandish raps and earworm melodies, delivered with the most insouciant pout since Anna Tsuchiya. It's a slicker and less pugnacious record than her 2017 debut, "Miseinen" ("Underage"), with one eye on the international market and the other checking itself out in the mirror.

On "I'm a Pop," she responds to criticisms of last year's viral hit, "Doctor," with a shrug and a flip of her middle finger, while spelling out her approach: a bit of pop, a bit of rock, a bit of hip-hop. Midway through the first verse, she slips coolly from Japanese into Korean, as if to say, "Sure, I can do that too."