First of all, a little follow up and warning about 推し、燃ゆ - it ended up being too hard for me, I’m postponing it for now.
I also wanted to thank everybody reading along for lengthy discussions. It was extremely satisfying and made reading it as a book club worthwhile.
It was already mentioned both in the original Home Thread and by me and Belerith during one of the previous weeks, but I want to remind of and recommend コンビニエンスストア様 to anyone who finished.
It’s free in an e-book version:
Kindle | Bookwalker
But you can also order it as print-on-demand on Amazon.
It’s an extremely short (only 7 pages of text in the print version, the rest is just a filling) love letter sent to the コンビニエンスストア. It has sort of magical realism elements, with the store being anthropomorphic. It ties-in very nicely with コンビニ人間 and it’s very fun to read.
Official translation does exist and is also available for free.
As for my impressions about the ending and the whole book.
I liked the ending, and I think it is a happy ending, just not a perfect one. In a perfect one, she would be promoted to some sort of upper manager, responsible for supervision of stores in the whole area, I guess.
That way she would get both “respectable” job and she would be able to help fulfilling konbinis’ desires.
But the real ending is much more realistic and grounded. It’s about being happy while choosing what’s available, getting to know one’s limits and not spending whole life chasing what’s impossible to get.
Trying to challenge yourself might be nice, but I think there’s a lot of worth with just settling with what you have and enjoying daily life. Especially if said challenging is only making you miserable, like what was happening with Keiko.
Even if after all she is just doing what she was doing at the beginning of the book, now she knows that alternatives are not for her. I think it’s great that she tried these alternatives, because previously she was continuously feeling doubts about her life choices, but I love the fact that after all her solution is accepting the fact that she’s コンビニ人間.
Of course, it wouldn’t be so great if she would be genuinely unhappy with her life, but that’s not the case here.
While I know that the character and the author are separate beings, it’s hard not to compare them due to the fact that Sayaka Murata also worked very long in コンビニ (and also because of previously mentioned コンビニエンスストア様). So I find it very sad that Sayaka Murata herself had to stop working in a store because she was bothered by fans.
Murata also comments on their similarities in this interview:
“People think she is having a hard time, but she is so pure, she doesn’t care at all. She has no doubts. I wish I could live like her, and not think about others,” says Murata, who is herself single and lives in central Tokyo.
I also wanted to comment on the title. I love it, and I’m sad it was lost in translations. To concentrate only on the English one, I think “woman” simply doesn’t fit, because focus on her gender is exactly what was bothering the main character. But I understand that “human” was deemed as too weird of an option.
Between Japanese titles, I can’t not compare it to Dazai Osamu’s 人間失格. Of course, the “feeling like an outsider” is not that rare theme, as seen even a few posts above, but since these two books share 人間 in their titles, and both contain autobiographical elements, I want to compare them. (There won’t be any spoilers for 人間失格.)
While the MC of コンビニ人間 finds solace in calling herself a different species, MC of 人間失格 is, just as title suggest, feeling disqualified as a human being, but struggling with finding an alternative. Between the two, Keiko definitely seems like a winner and actually I would love to read a fanfiction where Keiko meets 人間失格’s MC. 
(And no, I’m not writing it myself.)
(And well, between the respective authors, from the outsider’s perspective, Murata also seems to lead a healthier life when compared to Dazai.)
And if anyone’s interested what Sayaka Murata herself thinks of Dazai’s works, we actually know the answer from this interview:
Your top five authors: I believe that novels are only completed once they become music within their readers. I can’t judge an author simply because I was not able to properly perform their music. Books that didn’t resonate with me probably provided someone else with a wonderful musical score. However, the authors who have given me wonderful music, especially when I was a college student, are Rieko Matsumura, Albert Camus, Kobo Abe, Yukio Mishima and Osamu Dazai.