Be goog to a loli, and the loli will be good to you.
Well, I think that sumarize the hole story... This manga is a sort of... Loliconness apology? Sex with elementary schoolers is fine as long as both parties agree. SM is fine, incest is fine, enkou (enjou kousai) is fine and so on.
Well... Let's say a little more about it.
/! SPOILERS AHEAD /!
The story revolve arond a elementry school girl trying to convey her feelings to the one she loves. Except things don't go so well with the appearance of a tentacles monster and a tryst she beholds by accident. Then you
have the serie of loli's gangrape caused by the monster and his children and some old pervert who takes advantage of the situation. Be warned that the story absolutely don't end in a moral way, but in a completely different way that that of a standard lolicon story containing consensual sex, or even rape... This work could even be called subversive as far as I'm concerned ... But well, I did enjoy the scenes so... Not one to talk...
All in all, I'd give the story a 6... It wasn't average, nor was it good.
Same for the art...
And the characters were... Well... Not so good, but I enjoyed the monster queen as well as seeing the girls fall in the depth of lust. So 7
Overall, it was a not so good manga, a little fucked up, but quite enjoyable. Just don't read it if you're not at ease with what feels subversive.
And as I said, I enjoyed very well the series, let aside the ending.