bruh

Won't that be plagiarism? Also, I doubt short mangas get anime adaptation. I guess anime movie does though.

yeah im pretty sure it would be!! this mangaka is a haikyu fan so basing their character designs off of kagehina was their goal so i guess they never had any intention of it getting a future movie adaption

While the colour of the hair is similar, the hairstyle itself isn't, and the characters still feel different enough to be their own. The similarities are undoubtably their, but there's enough variation to be Himekawa and Hirono not Hinata and Kageyama.
Short manga can always just get a small OVA serise rather than a full anime adaption, so length isn't a reason. Though it's still unlikely it will get an adaption done anyway, it's not impossible after all wasn't Given also based on kagehina, and that got it's own anime

I meant the design. Yes, the characters' here and on Haikyuu are completely different, but there's no denying that they look like them. Seeing that there is evidence since the author does Haikyuu doujins, there is no coincidence and I think it's plagiarism (the artstyle is different so I'm not sure). Given's characters don't look that much like them, except for Haruki (he looks so much like Asahi).

If you look at the character inspired by Kageyama in Given, the hair parts the same way, while here the style of the character hair is different, you can tell by the fringe. The one inspired by hinata also looks different by having much smoother hair.
In my opinion it's not plagiarism, it's mearly insperation. The characters aren't just copies, and the ideas behind everything seem to be the mangaka's own. Though I do agree Given's art style helps make them look more different overall.