This film premiered in the US at Otakon 2023.

It’s not uncommon for people to dwell on what might have been. “If only I could get back what I lost, then everything would be better.” The Tunnel to Summer, the Exit of Goodbyes is an anime film that explores this feeling, told through the lens of a summer romance with a spark of the fantastical.

The Tunnel to Summer explores the lives and relationships of two teenagers, a boy named Touno Kaoru and a girl named Hanashiro Anzu, who end up finding an actual urban legend: the Ryuuguu Tunnel that is said to give you your greatest desire but at the price of losing everything. Touno has to deal with an abusive father who blames him for all their troubles and trauma. Hanashiro has something to prove and an attitude to match—one that says, “I have neither the time or patience to deal with stupid crap.” The pair discover that time passes much more quickly in the tunnel, and even a few seconds in there translates to hours in the real world. But the two have wishes they want to fulfill, and so they work together to figure out its secrets, all the while growing closer.

Time dilation isn’t a new premise in Japanese fiction. Both Aim for the Top! Gunbuster and Voices of a Distant Star explore how human relationships can be affected by the uneven passage of time within science fictional settings. Even beyond anime, the Ryuuguu Tunnel itself is a reference to the fairy tale Urashima Tarou, which is about a guy who visits the underwater Ryuuguu-jou (Dragon Palace) for what he perceives as three days but is actually 300 years. As a trope, I actually enjoy time dilation quite a bit because of how it messes with our minds so simply and easily—and The Tunnel to Summer adds another emotional dimension because it’s not just about how they are passively affected by it but also how their active decisions have consequences. The characters must consider how the past (or future) they long for might very well be distracting them from finding happiness in the present. 

Something else that stands out to me is the central relationship between Touno and Hanashiro because of how much the two feel like equals. It sort of brings to mind BL shipping in shounen series, and how often it happens simply because all the boys are involved in the same competition—which often engenders visibly greater passion than whatever interaction the hero has with a female love interest. Here, Touno and Hanashiro feel very much like they’re in it together as they learn and experiment about the Ryuuguu Tunnel. In terms of how this plays out in the overall story, I like how each character is very invested in their mutual endeavor in their own way. The similarities and differences between the two ultimately enriches their relationship and gives the film a nice emotional anchoring.

Because of the subject matter and the seasonal setting, The Tunnel to Summer, the Exit of Goodbyes ends up having a very nostalgic feel while at the same time questioning the value of nostalgia itself. It’s more than just another summer-themed anime movie, carrying a memorable identity all its own.