Rea Masaki (正木 玲亜 Masaki Reia?) is a fictional character in the Tenchi Muyo! series and is only a character in the OVA continuity.
Rea Masaki is a distant cousin to Nobuyuki Masaki and a family friend. She had been taught cooking by Nobuyuki's wife Kiyone, so even though she does have her favorite recipes, her cooking style is identical to Kiyone's.
On the day of Kiyone's funeral rites, she was checking on Tenchi Masaki when she noticed the boy had disappeared. Everyone present searched around for Tenchi but couldn't find him. It was during this search that Rea thought of something. Taking Nobuyuki with her, they found Tenchi asleep at the entrance to the cave where Ryoko Hakubi was imprisoned. Tenchi was forbidden to go to the cave by his grandfather Katsuhito Masaki, but always went there anyway. Rea remembered this.
Rea would end up cooking and cleaning house for the Masaki, even though she was a high school student at the time. Sometime later, she would move in with Nobuyuki at an apartment near the site of the house that Nobuyuki designed during Kiyone's lifetime (that house would be moved near the family shrine, destroyed when Mihoshi crashed into it, and rebuilt at the same site). When the school which Tenchi attended was destroyed by fire, not to mention the Great Seto Bridge's destruction, she and Katsuhito were called to Tokyo to explain what had happened, at the Japanese Imperial Palace no less. At the last minute, Katsuhito backed out and Rea had to make the report herself. Months later, she revealed this fact to Tenchi when he came over for a visit, but when he asked her why, she said it was a secret.
At the last episode of the third OVA, Rea and Nobuyuki were married. Among the guests present were the Masaki clan, Airi Masaki, Minaho Masaki, and Tokimi. In Tenchi Muyo! GXP, she is shown to be pregnant. Her son, Kenshi Masaki, is the principal character of a Masaki Kajishima project known as "Saint Knight's Tale."