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.”

While “Miseinen” was primarily focused on flaunting attitude, “Never Grow Up” is more concerned with matters of the heart, and Chanmina’s is mostly getting broken. The catchiest hooks are offset by bittersweet sentiments. The title track, in which she calls it quits with a boyfriend, is a lilting reggaeton groove that sounds tailored for a Shonan beach party. The loping “Cafe” fashions a singalong chorus from the suppressed heartache of a coffee date with an unrequited love.

The album’s most vulnerable moment, “Pain is Beauty,” blends autobiographical verses with a soaring emo-rock chorus. It’s the kind of hip-hop melodrama that Eminem used to do so well, and the song’s emotive video gives Chanmina’s story the “8 Mile” treatment, depicting a delinquent teen who finds her purpose in music while making peace with her bullied younger self.

Not everything on “Never Grow Up” is quite so anguished. During the R&B-flavored “Can U Love Me,” she teasingly laments the fact that she’s too independent to find romance. “Like This” tests the waters with a potential paramour, in a delicious double entendre of a chorus that’s crying out for a lewd dance routine to go with it.

Musically, the album stays on top of recent fashions without getting ahead of them. The contributions by regular producer Ryosuke “Dr. R” Sakai are so on-trend that when Chanmina hooks up with LA hitmaker Marlon “Chordz” Barrow on “Can U Love Me,” it barely breaks the flow. But the cartoonish mash-up of “Doctor” is the most striking creation here, and “Never Grow Up” would have benefited from a few more weirdo flourishes.

The biggest surprise comes on bonus track “Sad Song,” in which Chanmina indulges her love of Avril Lavigne with a detour into pop-punk territory. It’s the kind of song that was probably more fun to make than it is to listen to, and one can only hope that it isn’t an indication of things to come.

Where Chanmina goes from here is anyone’s guess. Speaking to The Japan Times earlier this year, she expressed an ambition to take her music global. The songs are peppered with English lyrics, most notably on “My Own Lane,” an anonymous, auto-tune-heavy grind that doesn’t live up to the boast of its title.

If she wants to be the next Cardi B, she’ll need to do better than that. But in Japan, she’s already got it made.

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