When you work as a waitress at a Japanese restaurant, you should wear a kimono and white cloth socks and clogs. Female waitresses wear their hair in a bun. Men usually wear a plain bandana over their head, a plain Japanese-style blouse and pants, and an apron around their waist.
The kimono for women is a short-sleeved kimono that makes it easier to serve food and remove dishes, and the sleeves don't get in the way.