For the most part, “Pops,” the latest full-length from Mrs. Green Apple, sounds like textbook J-pop.

The trio’s sixth album sold 638,788 units in the week following its Sept. 30 release, , making it one of the year’s biggest physical sellers so far. That’s thanks in part to advance singles “Brand New” and “Good Day,” whose uptempo melodies and triumphant key changes generate positive vibes suggested by the LP’s title. (Both the album and band name are officially rendered in all caps.)

Spending more time with “Pops,” however, reveals a few sonic surprises. In a recent interview with The Japan Times, Motoki Ohmori, the vocalist, guitarist and driving creative force behind Mrs. Green Apple, described a slightly darker current running beneath many of the album’s brighter sounds.