f(x)'s Krystal showed support for her sister Jessica's debut novel 'Shine'.

Jessica announced her book was finally out after a delay, and her younger sister Krystal celebrated the accomplishment with her own fans on Instagram. On October 2, Krystal announced, "My sister's debut novel 'Shine' is out now," adding how proud she was of her.

The f(x) member also shared a photo of herself holding up the novel, which states on the cover, "All's fair in love and K-pop. Shine. A novel. From international K-pop star Jessica Jung."

In other news, Krystal is starring in the upcoming OCN drama 'Search', which premieres on October 17 KST.