主我 is read as しゅが (shuga) and means ego.
しゅが
shuga
しゅがしゅぎ
egoism
しゅがしゅぎしゃ
egoist
わぬし
you
しゅちょう
claim
しゅぎ
doctrine
しゅさい
sponsorship (i.e. conducting under one's auspices)
しゅしょう
advocacy
しゅうじゅう
master and servant
しゅかん
chief editor
しゅぎしゃ
-ist (i.e. adherent to a belief system)
しゅしん
chief umpire
しゅじく
linchpin