Summary on the title page is kind of misguiding. And it's not really drama or seinen, and nothing like cliche robot stuff.
Sorry for the loads of text!
Hatsuseno Arpha is a girl who runs a small Cafe Alpha in the remote country side. If she hadn't mentioned herself to be a robot we would never guess. Alpha's life is calm and slow-pace, yet anything but boring.
Mangaka Ashinano Hitoshi-sensei is a magician who drew and wrote the commonest things into beautiful and captivating story. I'm his fan, seriously.
Alpha enjoys drinking coffee, seeing her few neighbors, making new friends, riding her motorbike along overgrown roads, watching the sunset, swimming in the sea. She's kind, cheerful and optimistic. She lives through small adventures and little by little learns more about people and the world she lives in.
The world of YKK is some time in the future. It's strangely, incredibly beautiful. Because of some cataclysm in the past, the level of the ocean keeps slowly rising; there are heavy hurricanes and typhoons every now and then. Japan is isolated from the rest of the world. The techno era of skyscrapers, megapolises, media, virtual space and globalism has completely gone and was forgotten. Nature takes back its space, once conquered by civilization.
There are not many people anymore, and they went down to peaceful and simplystic, plain, living with doing simple jobs, growing vegetables, visiting each other, writing letters by hand.
What has happened in the past? Why is it so now? How were these human robots created and what for? Where is this world going to? This future world is full of mysteries for readers. The story slowly uncovers some secrets and keeps others.
YKK has very well-worked plot and the characters are plausible and very charming. It has many curious turns that open a new piece of that world. The manga somehow gives quite a few of simple, witty and wise observations on life and people. All the stories are very-very kind and nice.
If compared with Aqua/Aria, YKK is much more nostalgic, in a bittersweet way. YKK is also phylosophical, no less.
Art of the manga is not glamorous, but it offers pretty unusual technique of ink and pencils used together. Often, pictures speak instead of words and do that really well. The sceneries are quite sketchy but amazingly gorgeous and atmospheric. Grass fields up to the horizon, floating clouds, sparkling sea, old cosy cottage, overgrown ruins, tender hues of sunset...
I'ts like the best tradition of classic Japanese art. Like those classic scenery pictures with poems written on them.
YKK is very poetic.
"The world has changed a lot over the years. It looks like the twilight of this age has quietly arrived. I think I'll be around till these twilight years end." Alpha, Ch 001.
My further thoughts, spoilers
Basically, the setting is post-apocalyptic. But that's the most beautiful and peaceful post-apocalyptic world one would ever imagine. Along reading, it's getting obvious that the humanity there is voluntarily dying away. Very few children are born. But people are not really sad about getting to the end, they accept it and keep on living, still having and sharing their small joys.
Imo, that's a very interesting idea. Well, we all know that sooner or later life on Earth will come to an end.
And this manga takes an unconventional try to depict that "sunset" of humanity. The story is pretty ecological, that's very Japanese way of thinking too.
As humans are now, we conquer nature and build our own world above it. YKK shows a distant future era where humans have a completely different phylosophy of living. They don't have the idea of transforming nature but let nature take back what they once taken from it. Ocean floods cities, grass takes over asphalt. For that, to people Earth bestows peace, fresh air, clean world, comfortable living, balance of mind. It's clear that nature will outlive people, it's like the humanity humbly return to Earth, its cradle, in the end.
When this last era of people on Earth comes in reality, I wish it was like in YKK.
"The night of humanity... May it be a peaceful age." V.14. Ch.006