In "No Need for Resident Officers!" there are a few scene of her barefoot.
Episode 12EditIn part one of the "Universe time and space adventures" three part episode Kiyone (while as a feudal Japanese cop) is barefoot while meeting Ayeka about Ryoko.
Tenchi Muyo in LoveEdit
Kiyone's feet are the lighter colored ones, she is walking around while the darker-skinned Mihoshi is under the covers.