A new aww-inspiring obsession is sweeping through Japan these days, threatening to unseat delightfully doe-eyed kitties and fluffy pups from atop their adorable little thrones. It’s called “hamuketsu” — a mashup of the Japanese words for “hamster” and “buttocks”.

Yes, hamster bottoms are now a thing.

So far, two books exclusively featuring pictures of hamster tushes have together sold nearly 40,000 copies in the country known to be on the forefront of cute trends, and yet another is set for publication this month. There’s also a fast-growing Facebook page devoted to the rodent’s derrière that has attracted over 8,000 followers.

Takeshi Takahashi, a spokesman for one of the hamuketsu book publishers, tells the Wall Street Journal that he, personally, finds the sight of hamster behinds actually quite mesmerizing:

“The great thing about hamuketsu is that it is delightfully cute. I can’t stop smiling when I see these butts.”

There’s no denying that hamsters’ rumps are pretty darn cute, though the same could be said about the rest of them as well.