Gir's Last Tour is an amazing experience that I recommend you (the reader) to read it only 47 chapters with lots of interesting topics that you might even relate to. Scared of dying scared of forgetting scared of losing your loved ones is all an interesting topics that are mentioned either by saying it or just realizing it by yourself from it.

(Spoiler Alert)

Girl's Last Tour is a very interesting manga that makes the reader attracted to both MC(s) and how they keep on bringing back "What's Life?, Afterlife?, feeling lonely, hopelessness and loneliness" topics.

Girl's Last Tour takes a place on a world that lost Humanity because of a certain War both Yuu and Chi-Chan joined the War because of their Grandpa told them to and go to the surface (top place), after sometime the War has ended with all of Humanity to die only 4 are alive the 2 MC(s) and 2 random people.

Yuu and Chi Journey is a somewhat hopeless and helpless goal they don't even know if what they're doing is the right choice to live their lives but one thing for sure is they kept moving forward no matter what obstacle or challenge they face or the fact that the people who they once knew are no longer to be alive or even be able to live like before.

On their Journey they met two people and a weird animal...First of their encounters was Kanazawa who says that making maps is his life without them his life won't have any meaning anymore, unfortunately for him he loses his maps that he made and wants to die but before that Yuu and Chi try to help him as they are able to in the end Kanazawa moves on his life giving the both Chi and Yuu potatoes and his Camera as a thanks. There aren't much information regarding Kanazawa after he went on his path but it's safe to say that he killed himself.
Ishii is the second and last human the two find on their path, Ishii asks the two to help her finish making the plane she has planned after the success of her prototype plane, she says that she made the plane so she can leave the city and go far away where to you ask? she herself doesn't know she just wants to have hope of meeting others and living her life, after finishing turns out the plane was huge fail and she jumped of it with her parachute saying that she's happy because her goal has ended in a total fail. We don't know what happened to her after moving on but it's safe to say she died of starving or killed herself like Kanazawa.

Ket is an animal that Yuu has found which is not a normal animal his species are able to use radios to communicate with Humans also he eats bullets (idk lol).The 3 keep on moving until they find a submarine where Chi and Yuu went to discover what's inside in it they find a huge screen and Chi wanted to take a photo of the place she pressed the wrong button which made the Camera to connect to the screen and saw the many Photos and Videos that were taken from this Camera and have been in the memory of it, we see Kanazawa with a little girl (his son) and a women (his wife), other photo was his wife alone no sign of his daughter which means that she died because of the War...His wife probably died before Kanazawa met Chi and Yuu either him killing her or she committed suicide or she died a normal death. Other photos were from different people from another generation maybe 100 years ago.
In the Submarine the three find Ket's group in the Submarine telling the two that they're the only alive that they seen (meaning Kanazawa and Ishii have died) which Chi and Yuu did not realize that which is for the good since they're just kids, Yuu and Chi say their goodbyes to Ket and his group and move on.

In the end before reaching their final destination both Yuu and Chi have been holding both hands staying together and thinking of their lives and existence they're scared to die they're scared of being alone they're scared of losing each other, then they reached the top it was a total disappointment to both of them all that Journey just for a flat surface no sign of any one being alive only to be covered with snow. In the end they did all of this for nothing but that's not totally true since they're still alive and have each other.

Aftermath : the writer drew them in a grassy field being happy.

GLT has it's issues like the ending and the lack of information about the world and the war, but the writer focused more of the message of the manga which is "feeling alive" they have lost their Grandpa the people that they've met but still they kept on moving forward even with the crushing disappointment in the end they still kept moving forward and be happy as long as they're together they won't be sad nor feel lonely.