Higa Takeru

Higa Takeru is the Chief Developer of the «Soul Translator». He works under Kikuoka Seijirou in RATH, using «Underworld» as a means to create a «Bottom-Up-AI», by nurturing a mass number of Artificial Fluctlights, in order to further Japan's military force.

He claims his reasoning for doing so was that a friend of his had gone and joined a war, only to die.

Background
Higa went to university with Kayaba Akihiko and Koujiro Rinko. He was the last student of the Shigemura lab in the «Touto University of Electrical and Electronic Engineering» which had two prodigious figures: Kayaba Akihiko and Sugou Nobuyuki.

Versus
In this side story he talks with Kazuto before he enters the new Full Dive technology machine, and tells him about the ghost that other users of the machine have seen.

Alicization Turning
Asuna encounters him and Rinko following a robot named Ichiemon through a set of spiraling stairs that connect the Ocean Turtle. He later explains to Asuna some aspects of the Alicization Project and for what the robot he was making was needed.