I want to cum in Kumiko's socks!
You mean with Asuka? Yes, since episode 1.
She isn't just genki though, she acts like an actual autistic person. Like, there was an autistic girl in one of my university classes and she acted just like this. Complete lack of social awareness and unable to keep her mouth shut. Even down to the overdone stage voice and manner of speaking. Shit got old real fast.