MAMAMOO's Moonbyul is celebrating her birthday by giving fans the ultimate present — a special song!

On 22nd December, MAMAMOO dropped a surprise song, 'CHEMISTRY', for Moonbyul's birthday.  

[#문별]

🎊 HAPPY MOONBYUL DAY 🎊

💙 211222 우리 무무 여러분의
겨울을 매번 따뜻하게 맞이해 주는
별이의 생일을 사랑으로 채워주세요💙#30thByulScene#소중한겨울아이_문별이_생일 pic.twitter.com/pwTQRONgW6

— 마마무(MAMAMOO) (@RBW_MAMAMOO) December 21, 2021

The song also comes with a music video showing Moonbyul in an old-school diner as she closes shop for the day and parties by herself in the wee hours of the morning. 

[#문별]

⭐ MOON BYUL - 'CHEMISTRY' ⭐

🔸 HAPPY B-DAY SPECIAL GIFT 🔸

🔗 https://t.co/3a2ilJMTJU#MoonByul #CHEMISTRY pic.twitter.com/M64NSPTClD

— 마마무(MAMAMOO) (@RBW_MAMAMOO) December 22, 2021

MAMAMOO just refuses to let us catch a break with their surprise releases and special songs for us. Earlier in the year, the Moonbyul dropped special collaborative track, 'G999' with South Korean rapper and songwriter Mirani, revealing she can sing just as well as she raps. Member Wheein also partnered up with Ailee to give us 'Christmas Solo' for the holiday season.

This year, MAMAMOO not only dropped their comeback album I SAY MAMAMOO: THE BEST, as well as their Japanese EP WAW, and the Japan edition of their album TRAVEL.   

Watch Moonbyul's 'CHEMISTRY' music video here: