The circle is complete. Josh DeSeno made his emote "Kappa" in reference to the Kappa Youkai. Twitch found it and went "what the fuck is a Kappa?" and then it caught on as memes tend to, because the semi-mocking smile fit in perfectly with the gamer culture of doing just that.
Now Japan's favorite Kappa has found it, and is having a similar reaction. The circle is complete.