Ranma ½, Orange Delivery Recommendations
Ranma is nuff said but I find that there are very few manga that come close to being similar to it. This is one of them.
Note that unlike many of Ranma's recommended section, I'm not comparing Orange Delivery to the genre of gender bending nor am I solely focusing on the love comedy bit though OD is a sports comedy manga.
What makes these two similar is based on my overall enjoyment on the characterization of both manga and the quirkiness behind both of them. You're not going to find a concrete similarity to the two but as far as fast paced comedy mixed with weird