This manga is awesome. Screw people who disregard it as 'inappropriate' and deem disrespectful towards the Japanese culture, just screw them all. It's funny, playful, heartfelt and weirdly endearing. The jokes might be directed towards adults but that doesn't mean they're bad, not at all. After you get to know the characters, you will fall hopelessly in love with them in an innocent way of course, and you realise you just can't leave them alone. Some people I know complain about the art and laugh at how simple and straight-forward it is, but that is what I actually feel would suit this story in the best way possible. You wouldn't want to see your beautifully-and-in-detail-designed characters poke their butts in your face would you. Besides, it's that honest and down-to-earth feel exuding from the artwork that really compliments the kind of story this is (kinda reminds me of Chibi Maruko-chan, another classic).
The manga as a whole stays true to its nature, being a black comedy, and remains one of the finest in its genre. I pray my sincerest wish that the mangaka had RIP for all that he had contributed to this world in general and with this huge manga series in particular.