The exact anime source of this line is not documented on the soundboard, so it is best known simply as San's 'Kiiro no Sumieru' shout, a Japanese phrase meaning yellow smile. Short energetic voice clips like this one travel well on meme and soundboard sites, where they get reused as hype stingers in edits and reaction videos. It sits alongside other high-energy anime voice memes such as the Re.Zero: Whoaaayeeeaaayaaai~ exclamation and Happy's WOW! from Fairy Tail, which serve the same role as a quick burst of animated enthusiasm.