It's a picture drama (basically just has audio accompanied by still images, though there is some very limited animation such as camera pans and zooms and a "page turning" animation between different images) where it seems Aeka imagines various Tenchi Muyou! characters in a story set in the Heian era of Japan. Irrelevant as far as I can tell to the main plot of the Tenchi Muyou! Ryououki OVAs, but completionists can feel free to watch it. It references a few stories and elements of Japanese folklore. In the end it finishes inconclusively as Aeka says she can't take any more of this world.