The thing is, in the second to last chapter, Chito and Yuuri really do feel at peace with each other after all of their adventures. ]They were near the end and threw everything away just at the last stretch, they rarely used the gun especially for actual threats, the Kettenkrad couldn't be fixed so they made the most of it by having a bath, and Chito's diary was just her realizing she collects too much books (and memories) to keep going. It really felt like all that mattered were Chi and Yuu, the description of the series says it all,
whether they're sucking down their fill of soup or hunting for machine parts to tinker with. For two girls in a world full of nothing, the experiences and feelings the two share give them something to live for...