So sad, but so good. It kinda reminds me of Koe no Kitachi, which was also so sad, but so good. They both have that hopeless atmosphere that punches you in the gut, but also leaves you with a hopeful feeling (if that makes sense).
As for tags...I think they're fine, but on the other hand - it's not a yuri manga, it's a manga with yuri. IMO that's a pretty big difference, though probably impossible to tag.
I wholeheartedly agree.. Don't read it for the yuri, but read it for the story. It's not a manga about lesbian relationships. I've only read to ch 19 so far, but I highly doubt it is going anywhere like "Happy End". Besides they're only 11 in here and romance is the last thing they're worrying about in the story.
Also the SP are Het, but they aren't canon (thus far) and the author himself says it's just for fun. I wouldn't worry about it. I'm thinking unless there is a time skip, that this will end with no romance...but who knows? Maybe we will get fucked over and he decides to throw in a canon het relationship in a one chapter time skip ending like "Happy End" But I'm hoping he has better plot writing skills than that...I at least have faith that even if it ends up het, it won't come out of nowhere, since you can already see it going either way right now.
Oh well, I'm liking it so far and I'm along for the ride. Thanks for the upload!