What IS the big deal for MC to call her using first name anyway. I understand it's Japanese tradition to show closeness or something, and I usually take the MC's side, but this chapter I'm on Uzaki's side. They've known each other for 5 years, and he even get permission from her to call her by her given name. Why do you need to blush and hestitate like an idiot, just say "Oh ok, Hana it is then".