is Akutsu and Na-chan going to have a story or what because I am wetting to read it.

i don't know if this answers you but I think maybe they will but for now ,the next few chapters until 36 they'll just appear like two times (if i remember right?) and there's no real developpment between them ,also i think their appearance is just to help risa and it usually lasts few pages only
The coming chapter are all going to focus on the main characters

btw i hope this isn't considered spoiler ? ;; if so then i'm really sorry ,i just thought of it now that it may be considered spoiler,i didn't think before i replied ,really sorry