Lol. Or just “Ja.” Although- it’s German. So for those who don’t speak German- it isn’t that easy. “Ja” is yes- but it doesn’t always mean yes. “Ich geh JA schon” is an example. “I’m already going..” it’s a reply for if someone keeps asking you the same thing. So the Ja there isn’t directly a “yes” but Ja can and is also added to some things for an emphasis.
or if you really mean it: jajamensan
はい
Like saying hi