Growing up causes change, both to oneself and the world around them, and that isn't always a positive thing. This story is about fighting to step forward even after losing oneself, and it does a great job doing so!
The biggest strength of this story is Rii-chan. Rii-chan is overall a simple character with complex details. She's realistic and lovable for it. Her struggles are what fuel the entire story--hence why her name is the title. Will she overcome her situation and find happiness? What conflicts will she run into, and will she surpass them? It's worth the read to find out!
At the same time, every other character feels basic in comparison. Tasumi, Rii-chan's childhood friend, is a self-insert with a kind and strong heart. Rii-chan's mom is a loving single mother struggling to help her daughter. Each character besides Rii-chan can be summarized in a single sentence without omitting anything. Is that a bad thing? Not exactly. It makes the moments of characterization feel more impactful when they do occur.
The other issue to mention is the pacing. This was a web manga generally released one page at a time, and there are some points where it can be felt. For example, it isn't uncommon to have a story going on while having every other page be something else entirely to keep interest. It didn't ruin my experience, but some people might find that off-putting.
9/10 I would HIGHLY recommend this for others to read, and it has a fluffiness and length that makes it easy to reread. Heck, I was going to read a couple of pages to prepare to write this review, and I ended up rereading the whole thing again! There are plenty of similar web manga to be found, but this one has been the best one so far. Please give it a shot if you can spare the 30-60 minutes needed to read the whole thing.