10 cm is a nice, but predictable love story overall. As you can likely tell from the title, the story is mostly about various plot contrivances that keep the main leads, Haruki and Miou, from getting together even though it's clear from the moment the series starts that they're already in love with each other. It takes a few twists, but you'll see them coming from a mile away. It's not necessarily a bad thing, since that just means it's progressing naturally in a way that makes sense to the viewer, but it also means that the series stays firmly within your expectations and never takes any risks.
Some of it can be a bit too contrived as well, such as a part where Miou's mother allows her to meet the person that saved her life, but doesn't tell her that the person is already dead and she's being taken to a grave. This is a completely cruel thing for her to do, and it's only happening to fool the audience watching at home. There is no reason at all within the show's internal logic for her mother to hold that information back and surprise Miou with it. Sometimes the drama seems forced or unnatural like this, like it breaks your immersion to realize that things are happening solely because they're Plot Developments for the benefit of the audience, not something naturally occurring within the story.
That sort of maximalist approach to melodrama is the norm in this series, but because it's only 6 episodes, it never gets to the point of being over-the-top or grating. The short season format works against it in some ways, as you don't get to know the side characters as well as you would like, but the gimmick of increasingly improbable events keeping the main couple apart would have gotten annoying if it had been dragged out to a full 12 episode season, so overall it's a positive thing that it was kept short.
The characters are a bit flat unfortunately, Miou is shy and withdrawn and Haruki is popular and brash. They get a little bit of development, but only a little considering how short the series is. Haruki's crisis of confidence about whether he wants to be a director is the most interesting development, but I also just watched a superior version of a nearly identical storyline with Touko in YagaKimi, so it suffers by comparison. All that being said, the main couple is still very nice and you want to root for them to be together. Even if the characters are nothing special, I was invested in their relationship and its eventual resolution.
The one place the series really stands out in a positive way is its use of insert songs. You get one in almost every episode and they always nail the perfect mood and enhance the scene they're playing over. The sound design, music and voice acting is all very well done, and those are things that I typically don't take note of unless they're especially great.
