Girls' Generation members definitely have a strong friendship, and Sooyoung has proven that her love for Tiffany is unchanging with the times.

Sooyoung uploaded a vlog that followed her through the process of picking out Tiffany's birthday present, which was a customized bathrobe. The vlog showed the lengths Sooyoung went to pick the perfect present out for her longtime friend, revealing their touching friendship. 

Check the vlog out above!