I did a little digging to try and see these arguments and people are like "She's way too short and looks like a child!!!" and to that, I can only really say is - Uzaki isn't short for a Japanese girl, it's that the guy is really fucking tall and lanky. The average height for a Japanese Woman is around 148cm - Uzaki is literally 150cm. It's not going to make her tall by any means but she's not a dwarf.
Whereas Sakurai is almost 6ft - which practically dwarfs her.
You even see in the anime that she's about the same height as a normal woman but the guy just towers over them