Two cute felines who have been trying to enter an art museum in Hiroshima, Japan, a few times a week for the past two years recently went viral online. The cats have yet to get past the guards at the museum’s front door, but their persistence has earned them the adoration of millions of people.

This adorable cat-and-guard game started back in 2016, when the Onomichi City Museum of Art in Hiroshima hosted a cat photography exhibition called ‘Cats – Mitsuaki Iwago Photography Exhibition’. Among the many human visitors who came to admire this collection of photos of street cats in various poses, there was also a black cat who, just like everyone else, tried to access the museum through the front door. However the vigilant guard on duty spotted it and shooed it away. The cute scene was captured by Twitter user @mikusuke, who later posted photos of it online. They got thousands of likes and comments, but there’s really nothing unusual about cat pics going viral. What no one anticipated however, was the black cat’s persistence. For some reason it has been coming back to the museum and trying to get inside every week for the past two years, and at one point it even brought a friend.

Photo: @bijutsu1/Twitter

According to the guards at Onomichi City Museum of Art, about a year after the black cat’s first attempt to enter the venue, another red cat adopted the same routine, and since then, they have been taking turns showing up at the front door at least two or three times a week.

The two cats’ ongoing “war” with the museum guards is well documented on Twitter, where fans of the two felines constantly post photos and videos of their frequent visits. So far, neither Ken Chan ( black cat) or Gou Chan ( red cat) have been able to bypass the guards, but their persistence has made them so popular that the museum adopted them as mascots and now sells cat-themed memorabilia at its gift shop.

According to Twitter user @jiffington, the museum security guards sometimes spend most of their days trying to prevent Ken Chan of Gou Chan from entering the building. They are always gentle when removing them, and even stroke them behind the ears, but it’s now become tradition to prevent the felines from accomplishing their goal.

It’s unclear what keeps the two cats coming back to the Onomichi City Museum of Art, especially after two years of failed attempts to get in, but everyone seems to love their perseverance.