(Using image from: http://asianwiki.com/From_Me_to_You)
The one thing that the live action adaptation doesn't have that the anime/manga has is the comedy, but I can understand why they went to make it more serious. It would make the presentation of the movie out of place, and not appropriate to tell the story when transitioning between the heavy and light hearted scenes. There are light hearted scenes that make you smile or laugh, but it was adapted to be more realistic. I guess they toned it down a bit. I like the cinematography of how the scenes are shot. It showed the town the characters lived in from various angles which made it look good, and I'm sure they use some sort of filter to adjust to the setting of the story.
Overall, I still enjoyed the film. It's a very heartwarming film that is sweet and emotional. It leaves a smile on my face when the credit rolls in at the end.