Also I didn't really have any notes throughout the series, but one thing of note is that they're probably from a place in japan with a dialect, with Haru ending some lines with -be (-べ)instead of the usual -darou (ーだろう). I don't really know much about dialects so I can't specify where but I thought it was neat.
Asahi also contracts her desu's a lot, shortening desu (です)and desuyo (ですよ)to ssu (っす)and ssuyo (っすよ), which shows how informal her tone is. I guess you could also tell by how she refers to Haru by first name and without the "senpai" honorific, which could also just show how close the two are.
anyways thanks for reading and make sure to show the author some love if you wanna see more!