TWICE showed their unchanging love for ONCE.

In a cute video, the girls all wrote letters to their fans. The video started with cute, behind-the-scenes photos of the girls being goofy, and then ended with an individual close-up shot of each member as they wrote their loves and sincere love to all their fans. 

This is just the first of their four 5th-anniversary videos, as they've got something planned for every single day this week. So stay tuned for more as you enjoy the video above.