Just started reading, but I love this. Agree that Tanaka isn't a funny character in himself, but his resolute disinterest and (seemingly strategic) incomprehension enable Ueno's parade of humiliations. Which are funny af. For ex, Tanaka's escalating insistence in chapter three that Ueno's tights smell not just ordinary sweaty-socks bad, but stinky, awful, rotten!, etc. He's not saying or doing anything particularly funny; the comedy lies in her feelings and reactions.
And yeah, the scanlation is excellent. I really appreciate the explanatory notes at the end of each chapter. Thank you, Bainhardt 😘