Blair Russell’s review published on Letterboxd:
This is simply a nice and sweet movie.
That was the main impression I got from this tale, which is set in late 50's Japan but could be set anywhere, the setting is so timeless. It is a loving family that has to move to the countryside to be closer to the mom, who is in the hospital with an illness never mentioned in the film (as I understand, the novelization says it is tuberculous; Miyazaki himself experienced the same scenario with his mom when he was a kid). A few months is spent with the dad and two young daughters, Satsuki and Mei. They are typical all around in how they act and interact with each other. The siblings have their disagreements but they ultimately do love each other.
The movie is about more than just the two girls meeting all those magical creatures of the forest (including the titular Totoro); it is about seeing the two girls acclimate themselves to a new world. Of course it's sad their mom isn't around but they try to make do and the area does look like a lovely place to be. They get to meet some new humans too-including a boy that likes Satsuki-and it is heartwarming seeing them in that world and be a loving family. Describing the plot may make this seem mundane... and indeed this is filled with routine events yet at the same time it is so magical. As others have mentioned, you just might reminisce about when you were a kid and summers were carefree and fun.
No surprise this is beloved by so many between the gentle yet deep story, the characters, the beautiful animation and the delightful score. This movie did not need an antagonist or any other contrived-for this story, anyhow-moments to be engaging and it is a world I wish I could have experienced when I was young; at least further visits to this universe will be charming and pleasant journeys.