Thought the ending was decent all things considered.
I like how Miki changed her hair and clothes to match Shiko, subtle way of showing she's following in her footsteps. Along with the less subtle Yuki matching Megune.
The series definitely had some focus issues. Felt like the author wasn't really sure what they wanted to do, the whole university arc was pretty much pointless.
Lots of teasing at deeper themes and subplots but turning away at the last second.
Felt like they lost the nerve whenever there were difficult decisions to be made and instead offered an easy way out which is disappointing since that's the whole point of a series like this.
A bit of the Mary Sue effect, seemed like only side characters were allowed to do morally questionable things. The darker parts they had were probably the best part of the series. Finding the gun, Rii's sister, Yuki's delusions, Miki's cynicism, the evil girl at the college.
I can't tell at the end exactly what Miki's job is. Sounds like she one of the scouts in the Walking Dead who travels around checking the status of places, settlements and recruiting people.
If so she would be a good candidate for a spin-off, can't say the same for the others since it sounds like they have relatively normal jobs.
Wouldn't hold my breath for another series though considering they seemed to be struggling with this one as is.