[quote=Cuco]
Using someone's last name is more respectful. Using someone's first name is more personal. If Kaminari doesn't consider Akemi a good friend, he should use her last name. Considering Akemi, I would think that's the more likely case XDI'll get back to you on that backstory thingy in a bit.
[/quote]

Last name is seen as formal and respectful and it better to use San and sama if you use her last name. Because Kun and Chan with first names are more personal.
 
[quote=Sho Minazuki]
I just stick to the way we do it in English.Unless we're all speaking Japanese.
[/quote]

Yeah, after the first meetings with each characters, I will stop using them, it just my way of showing how he views each characters at the start. Just assume he using them after that point.