You really have to read the author's note at the end to truly appreciate the relationships displayed between these characters. It's one of those things that bases stories and characters on emotions and relations rather than pre-determined tropes, cliches, and already well-known practices.
Glad that the author captured that family's stoic nature and interesting take on the post-story world. Not a big fan of "sex with everyone" and killing cute characters, but this I can appreciate.
Darn. Author's working on the best part. Also, "This is a doujin so anything goes." First time I've heard a character openly admit to the hentai logic.
~A lyric and a rhyme~
~for everything~
Mature kid who only got more mature over this experience.