From The Heretic Knowledge Vault
A member of the Elven Council (probably). He's seen for the first time in the aftermath of Ian's social call at Praenubilus Astu, as he and fellow councilor Skena receive reports from High Commander Yenhael and Commander Nisotta. He's the first councilor willing to entertain the possibility that it may be best to send the kidnapped Meji back home to Tsuirakushiti, and instructs the spectating Sarine to make it so. (Sarine, of course, insists on having her say on the general elven thing about secrecy and the Giant Magic Potato, which doesn't sit so well with the councilors.)
Masaki wasn't part of the earlier verbal jousting with Sarine in the council chambers, although there was a male elf (by elimination, either Ameurin or Famair) in play at that time. This may explain why, unlike Skena, he doesn't find Sarine's loud complaints about the way the elves are behaving to be sufficiently annoying to blow up at her -- yet.