Founder Masaki as she appeared in her youth.
Masaki Raregroove was the first mortal to study and harmonize with one of the Royal Trees of Jurai. It was thanks to her that her brother, Emperor Sunshine Raregroove, and Emperor Rayleigh Glory were able to bond to the trees, and ever since, the trees have assisted in the growth of the Glory-Raregroove family in return for the family strictly adhering to the responsibility of maintaining order and protecting the weak across the universe. Masaki once spent three centuries straight researching the Royal Trees and compiled her work into the Arboretum Notes. In 150,082 CMT, Leviathan recited this information about Masaki to the Varia.
By 150,082 CMT, Masaki Raregroove was still alive in some form despite her advanced age and had become the head of the Juraian Records, the Prima Librarium of Jurai. An artificial intelligence that welcomed visitors to Jurai informed Ulkesh and Chirox that the current Emperor, Azusa Glory, often visited Masaki Raregroove for advice. The AI also encouraged them to visit Masaki in the Juraian Records for more personal information about Jurai should the need for it arise, and commented that Masaki found it entertaining to search for the most reclusive nooks in the Records, which were the size of an average city. Azusa himself later revealed to Ulkesh and Chirox that Masaki still played an active role in Juraian politics, describing her as someone who could "keep a hard line in negotiations" and someone who would not let anyone bully other speakers around.