Before saying anything I want to mention that I will be comparing this to the novel a lot, so with that in mind lets get on this. Natsu e no Tunnel, Sayonara no Deguchi tells a story of Kaoru Tono, a highschool boy with a dysfunctional family caused by the death of his sister. By accident, he stumbled upon a tunnel during one of his walks that seemingly is able to grant any wish for those who ventured within it.
As you may have guessed, the story revolves around the heavy theme of grief and self doubt. I think the movie does portray the theme quite well with its two protagonists Kaoru and Anzu. They're similar in a way that they have one strong wish, so strong that they're willing to risk and throw away the things and time that they have now in order to attain it, and it's definitely fascinating watching how the two affect each other and how they get over the underlying wish that they have. And in this sense I think the movie manages to do the novel justice.
This anime has really good visuals and animation. Coupled with decent play in music and performance by the voice actors, and refreshing character design makes the movie quite a feast in the eye to look at.
With that said, there's a major issue in the anime. That is the pacing. Although I liked how they handled Anzu and Kaoru's story progression, there's one character they forgot about. Yes, that character is Koharu. The anime basically cuts everything related to Koharu and her scene in the anime, which is unfortunate because her character plays an important part with adding even more depth to Anzu's overall character. And as a result some scenes may feel rushed.
To summarize, the anime is a flawed yet still enjoyable adaptation of a novel of the same title. If you have the time, definitely pick up the novel. But otherwise, Natsu e no Tunnel, Sayonara no Deguchi gets a 8/10 from me.
