Tennyo Masaki, daughter of Nobuyuki and Kiyone Masaki, is the older sister of Tenchi Masaki and half-sister to Kenshi Masaki. Her Juraian heritage grants her a youthful appearance mirroring her late mother, despite being approximately 80 years old during her debut in the third OVA series. This longevity allowed her to occasionally pose as Kiyone for interactions with the young Tenchi. She departed Earth after Kiyone's death to avoid human suspicion over her lack of aging. Her return coincides with the arrival of Tenchi's fiancée, Noike Kamiki Jurai, an arrangement by Seto Kamiki Jurai. Following her grandfather Katsuhito Masaki's mandate, the Masaki family conceals their non-human traits and extended lifespans from Earth. Tennyo adopts an elderly disguise for interactions with outsiders, such as during a class trip to Hawaii. She later returns with her grandmother, Airi Masaki, for Nobuyuki's wedding to Rea Masaki. Professionally, Tennyo works as a young Philosopher in one of Airi's Galaxy Academy production workshops in space. There, she designs components for the original Kamidake, Seina Yamada's first ship in the *Tenchi Muyo! GXP* storyline. Her resemblance to Kiyone leads Seina to briefly mistake her for his mother when she comforts him after Miki Steinbeck's apparent death. In the later continuity of the fourth and fifth OVA series, Tennyo is in a relationship with Hakuryo Masaki, a childhood acquaintance from Masaki Village who also joined Airi's workshop. Their relationship faces challenges from infrequent meetings and Airi's presence. Shifting her focus, Tennyo investigates her mother Kiyone's research on dimensional travel and Rea Masaki's origins from the parallel dimension planet Geminar. This includes altering her hair color from its original black, potentially to distance her appearance from Kiyone's and avoid recognition. Her activities intersect with broader events, like Kenshi Masaki's preparation for transport to Geminar, though her direct involvement in his training is minimal. She remains the only individual permitted to address Airi as "grandmother" without objection.