I’ve been remiss.

A year ago Thursday, I let you in on one of my guilty pleasures, BABYMETAL.

This time last year, they were a cult phenomenon, little known outside Japan. Not unreasonable for an idol band, however genre-atypical their music might have been. Those of us who had stumbled over the group wondered if they would survive. As I said, “It’s rare for an idol to have a second CD; the labels that control their “career” would rather promote a ne face who can sell the same merchandise again.” I also noted the notorious interchangeability of idols: it’s not uncommon for a group to last years, or even decades, with members aging out and being replaced by younger faces.

Well, part of the question has been answered. On April 1, BABYMETAL released a new CD. On the second, they kicked off an international tour in London. They made their American TV debut on The Lat Show with Stephen Colbert on April 5.

The media blitz is working. The Colbert appearance is currently the fifteenth most popular video on Colbert’s YouTube channel. Many of the concerts are sold out* and the new album, Metal Resistance is selling well: it debuted at Number 39 on Billboard’s “Top 200 Albums” chart and has been Number 1 on their “World Albums” chart for the past three weeks.

* Yes, I’m going to the San Francisco show. Silly question. Maggie and I are stocking up on earplugs, and are looking forward to seeing how they scale down their stadium-level show for a smaller–and less fireproof–venue.

How is the new album? Pretty damn good, actually. The girls’ voices have matured, and they come across as more confident and comfortable in their roles. There’s a good mix of styles, even the track I hated on first listen, “Sis.Anger,” is starting to grow on me, and the closing track, “The One,” is not only a hell of an anthem, but also an impressive earworm.

So signs are good for BABYMETAL to hang around for a while yet. If Amuse Management can resist the temptation to tinker with the membership, I may even feel justified in dropping that word “guilty”.

Will they resist? It’s true that as the girls age, they lose a bit from the “cute” side of their “Cute Metal” branding. Musically, that’s not a bad thing, but from an idol perspective, it’s a potential problem. On the positive side, there must already have been some discussion of tinkering to maintain the group’s image before they went ahead with planning Metal Resistance and the current tour. That would have been the logical time to make the change: bring in a new slate of younger performers and release a “BABYMETAL II” album–more of the same instead of trying something new.

Hopefully that decision will stick. I’d love to see BABYMETAL make the jump from metal idols to metal musicians, making room for a new crop of idols to take up “cute metal” and fill that guilty pleasure niche.