Oukaya Shigure from Yoshiwara Higanbana.
I will never understand the things he did. If you like a girl, just pursue her properly. What the hell were you even doing, you jerk?!
I seriously considered picking this guy in my first post. I thought some of the other LIs in Yoshiwara Higanbana had their jerk moments but Shigure is #1 jerk supreme, no competition. And I agree, I do not understand why he thought what he did was a good idea?? I very much questioned both his and the MC's sanity during his route.