I really think Himeno needs something else to her character to make her relevant againg. The manga has her name in the title, the author can't just act like she is a background character.
This manga is walking a thin line between tropes/cliches of romcom harem and a plot that moves forward. The questions are: how long it can keep up bringing new stuff and resolving it in a flash, what is going to happen with character development and where are their relationships heading
I think I said this already but that female teacher is like the music teacher from Whiplash
Also that panel in pg. 42 of the music playing is just breathtaking
Also also I WANT TO HEAR THAT FKING SONG NOW!