This is a very good but very flawed work. It has some high highs, some low lows, and a lot of confusing plots and periods of pacing. To put it simply, I wanted it to be better than it actually is.
Funnily enough, I think the characters are fairly weak in this story as a whole; they should have been more than who they were. Sumika is a strong almost perfect girl that "isn't cute." She is the epitome of a teenage girl, and I think that is a good thing. She knows who she wants to be but can't: a cute girl that fits Ushio's partner preference. She struggles between wanting to be close to Ushio as a best friend while wanting to be able to express her love to her. Ushio is that sunshine-smiling girl that overcomes her struggles as a girl who loves girls that never shows what's wrong to others, but there is a tragic struggle that haunts her past. Luckily, Sumika is there to help her through all struggles.. but maybe there's more? These two characters are fickle and wishy-washy, which gets pretty frustrating at times. Every other character is actually pretty simple, though that isn't always a bad thing.
So the story... It's a mixed bag. The beginning is really good and interesting as feelings are discovered and struggled with and against. Conflicts of the heart arise constantly, as one would expect of a teenage drama slice of life. The issue comes as the story continues, the pacing gets strange, and the characters begin to go back and forth. Honestly, the writing starts to work against itself, as it feels more fitting for an anime rather than a manga. Multiple events will be going on at the same time on the same page without distinction, and important events are given through flashbacks and in a very unclear manner. There are many really strong moments that are written well, but I still found myself asking, "So what was that about?" and "Wait, so what's going on between these two characters then?" A part of me wants to pretend that the bad parts aren't there to give it a higher score--one I wish it deserves--but I can't.
6/10 I.. still think this is worth a read. The strong emotional moments still has me recommend this series, but I say be cautious of the weird writing and pacing. Prepare to read some parts more than once to really understand what's happening, and it will help. It's good, but man there is a lot preventing it from reaching the greatness I hoped it would be.