The boys started tweeting the hashtag #UKISS5thAnniversary to celebrate the 5 years since their debut! The boys had a personal handwritten message from each of the members, from leader Soohyun to maknae Dongho.

SEE ALSO: Park Bo Gum's 'Good Boy' to air simultaneously on Netflix and Disney+ Korea, becoming the second K-drama to stream on both platforms

Soohyun wrote,

"It's our 5th anniversary~.... Thank you for always supporting us and let's go up to 50 years and 500 years. Also, Korean KISSMEs, I'm so sorry.. I'm going to work hard to definitely get #1 ?.? Thank you for showing love to the lacking U-KISS. Let's fighting together!! Fighting! I love you, my people..."

Kiseop wrote,

"U-KISS 5th anniversary. I'm happy today again because of our lovely KISSME. KISSME are always #1 in my heart. I love you sincerely."

Eli wrote,

"Thank you for supporting us for 5 years! I love you! Hehehe"

AJ wrote,

"Sincerely, congratulations on the 5th anniversary!! Our pretty KISSME are also 5 years old!! U-KISS ? KISSME FOREVER"

Hoon wrote,

"U-KISS' 5th anniversary~ For me, Hoon, I never want to be separate from KISSME!!!... Let's always be together, KISSME"

Kevin wrote,

"Wow! It's our 5th anniversary~ I have nothing to say but thank you... Really. I'm so thankful for always being with us, and thank you for always supporting us. I want to be with KISSME together forever~ I love you"

Dongho wrote,

"U-KISS' 5th anniversary!! Thank you for loving us for a long time~ KISSME are the best!"

Check out their photo overload below and congratulations to U-KISS!

Tip: Ruth