Indeed. Normalfriends need not apply in this strange relationship between a tall kouhai and a pipsqueak senpai (plus a weirdo four-eyes on the sidelines). 😅
Plus just have Oka be the straight man and not be a weird-yuri-thing.
Hell, she's the best fit for it as she describes herself as perfectly unremarkable in everything but appearance. (I wonder why the mangaka did that, really boggles the mind.)