The story
From Brandon + -nigger, in reference to the phrase let's go, Brandon.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A right-wing anime fan (i.e. weeaboo) who supports neo-Nazi or MAGA views, despite often not being of European/White extraction themselves (i.e. usually being Southeast Asian, Latin American, or South Asian) instead. Full definition →
From Brandon + -nigger, in reference to the phrase let's go, Brandon.
Etymology from Wiktionary, CC BY-SA 4.0.