I was looking up this picture for drawing reference purposes, and I was really struck with the fact that Momo is so much shorter than Izuru, but then it also struck me that Izuru is not that much shorter than Renji. So many horrible things happen to Izuru over the course of Bleach, but I think we often overlook the fact that when he met Renji it was like "ah yes, we are two guys" and then Izuru never grew again and Renji turned into Renji.

This is a splash page, so I thought I would see if I could find some further supporting evidence.

Exhibit B. Here, they are both very smol, but at least they are sort of equally smol.

Exhibit C. This one is very illuminating. For one thing, Momo is not nearly as small as she is in that first picture. For another, even though Renji and Izuru's head's are at roughly the same level, Renji is severely slouching, which isn't necessarily visible from a front or back shot. I love this actually, because Renji gives off the air of being very slouchy and skrunkly in his early appearances. He sort of alternates, actually, where he tends to stand up straight when he's trying to be intimidating or actually fighting, but then slouches and crouches and leans on things at other times. It's like he instinctually tries to take up less space than he actually does, except that you gotta stand up straight when Byakuya is looking at you, can you imagine having bad posture in front of Byakuya?

Anyway, Kira, I'm sorry. At least you're taller than me.