One ties up his hair to indicate acceptance of social norms on an official event. Or because it keeps poking them in the eye. Never having had any problems with unruly strands of hair, Lina now keeps the hairstyle as a reminder of the hottest ball she ever attended, it being the only single one.

Part of the "Charming Slayer" set we made for Polycount contest.
You can find the thread here:
http://www.polycount.com/forum/showthread.php?t=110368