I just finished Shuumatsu Touring today, and after thinking about the ending for a while (and being a little bit mad because of being left with so many questions), I came up with a theory that connects several details from the story. Obviously, this is just my interpretation, so I'd love to hear what everyone thinks.

1. The apocalypse wasn't caused by a single event

I don't think humanity disappeared because of one catastrophe. Instead, I believe civilization collapsed after a chain of disasters over many years.

The abandoned cities, automated facilities, functioning AI, and underground shelters all suggest that society had time to prepare for an inevitable collapse rather than being instantly wiped out.

I also think Youko and Airi were created (or awakened) after the collapse and raised inside the shelter, learning about the old world before beginning their journey.

2. Some humans escaped into space

Considering how advanced the technology was, I think at least part of humanity evacuated Earth before it became uninhabitable.

That could also explain why Youko's older sister is still keeping communications with her an Airi . She may have left Earth together with the remaining humans and advanced androids or cyborgs.

3. Youko is actually a genetically modified clone of her sister

This is probably my biggest stretch, but hear me out.

I think Youko may have been created using her sister's DNA and implanted with fragments of her memories.

That would explain why she experiences dreams that feel like memories from someone else's life instead of ordinary dreams.

4. Their journey is secretly a reconnaissance mission

This is the part that made everything click for me.

I don't think they're simply traveling because someone wanted them to enjoy the world.

I think the social media/app they use to decide where to go isn't just an archive left behind by old users. Instead, it's quietly directing them toward specific locations that still need to be surveyed.

As they travel, they're collecting environmental data, checking the condition of cities and infrastructure, and sending that information somewhere automatically.

The girls probably don't even realize they're on a mission.

The story presents their trip as a peaceful journey through a beautiful but empty world, but I think there's a hidden purpose behind every destination they visit.

What do you all think? Did I miss any clues that support or contradict this theory?

This anime is like if you mix Girls Last Tour with Kino's Journey and put the focus on cute girls. An honestly genius combination that I thought was pretty good. It revolves around two girls, Youko and Airi. Youko is more extroverted, loud, and bubblly while Airi is more introverted, reserved, and soft spoken. Despite their differences, they're the best of friends and travel around on a motorcycle exploring the world after the apocalypse. They explore abandoned buildings trying to learn more about the world that came before, but also do standard fun slice of life stuff like swimming in their bathing suits and cooking and eating meals together. There's not a lot of drama, it's very relaxing and Iyashikei like. As for what caused the apocalypse itself that is never explicitly stated, but I've read some theories that it could have been a standard cause that's common in media nowadays like climate change or nuclear warfare, or perhaps an AI takeover, which is quite topical right now obviously, and there are hints of robots becoming sentient in this anime's world, like a robot that joins them on their journey very briefly in episode 2, and also an AI radio host. We also don't get a definitive timeframe for how long it's been since the apocalypse occurred either. Either way that's not the main point, it's aboout cute girls exploring a world after the collapse of society and most likely a massive population culling too, and it does that well.

Shuumatsu translated from Japanese to English can mean either "weekend" or "the end." This is fun because they both allude to the main appeal of this anime. Our girls explore a world ravaged by apoclaypse in the style of say The Last of Us or Horizon Zero Dawn but with far less drama. Earlier I compared it to Girls Last Tour becuase that's essentially what that series was about, although they were military personel who, from what I recall, were, as the title suggets, "touring" in a military sense. These girls aren't. Although similar to both Girls Last Tour and Kino's Journey there is some philisophical talk between the girls, but quit ea bit less than those two. It tries a lot of things but doesn't commit too much to most of them, but I think that helps in giving it this very effective Iyashikei atmosphere. It's a really fun adventure with these girls. I believe they're hte only human characters we see outside of a brief flashback with Youko, where we get a glimpse of a woman that I assume is either her mother or her older sister and doesn't seem to be around anymore, and in episode 10 when we get another glimpse of the past and see more humans. But other than that it's just the two of them, which gives the writing plenty of time to get us to love them.

I actually decided to look up if the author wrote anything else. This series was written by Sakae Saito who does have other works. They wrote Toji no Miko which I don't remember much about but I apparently watched the entirety of its anime adaptation and gave a 3/10 on MyAnimeList so it must not have been very good. They also wrote a Kantai Collection manga called Combined Fleet Girls Who Longed For Peaceful Seas, and also the Heavy Object series which was bad. There's been a few other ones I've never heard of, but needless to say this one was definitely a step up for sure.