i really don't get everyone's reactions here. the story defies a lot of the "saving someone from bullying leads to romance" tropes. aki doesn't fall in love with iku-chan because iku-chan is saving her over the years. iku-chan just realizes she already loves aki when aki made some distance to save iku-chan with the bullies. no magic or heroic comeuppance came for the bullies, but staying by someone's side when they're being bullied really is all you can do sometimes. overall the story is understated in a pretty nice way.
I see what you're saying about the story subverting a few tropes, but it really didn't occur to me that the author might have been attempting to do that until I read your comment. I understand how you could find it refreshing, but I personally don't feel that the aforementioned tropes are all that bad or clichéd, so avoiding them doesn't do much for me, at least in this case.
I really agree with what others have said about the story feeling lifeless. Think about Aki as a character: she's essentially a semi-mute doormat, except for the one time she stands up for Iku-chan. Iku-chan feels a little more developed, but it's hard to find her very compelling when we aren't given any reasons for why she loves Aki. The dialogue is pretty bland. To call the art average would be generous. To me, this story is just forgettable. If I read it in an anthology, I'd probably just hope the next one would be better and quickly turn the page, rather than stopping and reflecting on it as I've done here. Putting the story under a microscope certainly doesn't do it any favors.