Tennyo is Tenchi Masaki's half-sister by way of his mother Kiyone. She is practically a perfect double of Tenchi's mother, save for their differing eye-colours. She was born and raised on Earth and only found out about her alien heritage late in life. After her extended lifespan started making blending with human society difficult, she left Earth to live on Jurai, only returning occasionally for visits.
Tennyo is mischevious, so much so that she often doesn't consider other's feelings until after she has played with them a bit. She also has a hair-trigger temper, particularly when her jokes backfire. Despite both these traits, she somehow manages to come across as one of the more mature members of the Jurai royal family.
While Tennyo is related to Yosho by blood and demonstrably has the extended lifespan of a Juraian it is unknown if she inherited any of the other powers of a Jurai noble. She never demonstrates any superhuman powers in the series.