Girls' Generation member Jessica gave her sister f(x) member Krystal a heartwarming birthday message.

On October 24th, Jessica uploaded a photo onto her Weibo along with the words, "Krystal's 20th birthday! Thank you, Mom. She is the world's most precious and lovely child. Glad you were born, Soojung."

The photo is of affectionate Jessica and her actual little sister Krystal. In celebration of her 20th birthday, Krystal is making a 2 and 0 with her hands.

Both Jessica and Krystal look like they're not wearing any makeup, and there still isn't one flaw in their beauty.

Upon seeing this picture of Jessica wishing her sister Krystal a happy birthday, internet users commented, "It's nice to see Jessica wishing Krystal a happy birthday," "The birthday photo is heartwarming," and "Their parents must be so proud of them."

Krystal's birthdate is October 24, 1994, and she celebrated her 20th birthday.

Photo credit: Jessica's Weibo