Hamster Butts Are the Newest Adorable Trend Out of Japan

From the country that brought you cat cafes and soccer-playing robots comes the next big thing in cute: hamster butts.

The furry pheonemon known as hamuketsu is a portmanteau of hamster and ketsu, the Japanese word for butt. Hamuketsu became a hit in Japanese social media circles around the end of 2013 and becomes the latest example of Japan’s aesthetic for all things kawaii, or cute.

Japanese publishers latched onto this trend and have released two hamuketsu photo books in 2014 already, selling more than 40,000 copies combined. Photos from Why Are Those Hamster Butts So Darn Cute?, Japanese publisher Basilico’s contribution to this emerging genre, can be seen above, while additional user-submitted hamster butts can be seen on their Facebook page.

“The great thing about hamuketsu is that it is delightfully cute. I can’t stop smiling when I see these butts,” Takeshi Takahashi, a spokesman for Basilico, told the Wall Street Journal.

Keep calm and kawaii on.

Subscribe to TIME

Get The Brief. Sign up to receive the top stories you need to know right now.

Please enter a valid email address.

* The request timed out and you did not successfully sign up. Please attempt to sign up again.

Sign Up Now

An unexpected error has occurred with your sign up. Please try again later.

Check the box if you do not wish to receive promotional offers via email from TIME.

You can unsubscribe at any time. By signing up you are agreeing to our Terms of Service and Privacy Policy. This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Thank you!

For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.