@indoeskrim
No. The yuri will happen because of school's seat placement, Saki's personality and both of them live beside each other.
That shota just shorten the span. At the beginning its ok, he give her sister a little push that's ok for me.
But then if he gonna keep popping out every time, its ruining the yuri experience.
I would rather to have a story with a younger sister gives her big sister a little push at the beginning, might as well helps her big sister multiple times during their outing/dates but then she herself ended up getting attracted to Saki so both sisters ended up felling in love with the same girl.
Well... I can't say much cause the manga plot needs the little brother so fuck it. It's not that I'm hating the series it just leave me with bitter after taste.