After checking your lists, I get the impression that you value realistic and complex characters, psychologically driven stories and beautiful, rather "feminine" art (like in Shoujo, Josei and Shounen-ai or Yaoi). If I got anything wrong, please correct me.
Following this indication, I can second
Kami-sama ga Uso o Tsuku. by
OZAKI Kaori and
Watashitachi no Shiawase na Jikan by
YUMEKA Sumomo (aka SAHARA Mizu). They're slice-of-life, respectively slice-of-school-life series, and both of them match the criteria above more or less. The first story also features children as sole protagonists.
OZAKI Kaori-sensei's art is solid and her storytelling simple, yet expressive. But as you are sceptical towards child protagonists you might need some time to warm up to her manga. Be patient and some seemingly "childish" actions will reveal themselves to be quite mature considering a child's powerlessness.
In spite of her subdued shading,
YUMEKA Sumomo-sensei's art is vivid with delicate outlines and breathtaking watercolours. Her stories delve deep into the soul's melancholy, but you need to give them time to settle. So, while I adore her stories, especially
My Girl (SAHARA Mizu), most of them might be too calm and slice-of-life-ish for you. Same goes for
Otoyomegatari and
Mushishi.
I agree that
YOKO's
Onani Master Kurosawa could be to your liking if you can come to terms with its sketchy art style. If you'd rather try some comedic slice-of-life drama - since Comedy, Drama and Supernatural are also well-representend on your list - check out
Molester Man by the same mangaka. You will hardly find anything more authentic.
Also take a look at
Ichigo no Gakkou by
SATOU Nanki/
KIZUKI Akira. Don't be misled by the description or the upbeat tone of the opening scenes. It is an exceptional piece of narration. Insights are filled with profoundness and realism as if literature was pressed between the covers of a manga. Don't let it go by if you can bear the roughly styled art.
ASANO Inio's
Oyasumi Punpun is one more challenging recommendations as it starts off as a slice-of-school-life manga with children as protagonists. However, it is one of the most uniquely mature series I know. The mangaka brings a surreal, yet startingly realistic quality to his work that is difficult to ignore. His narration might be desillusioned but not cynic: flawed characters, complex circumstances, urban setting. What distinguishes his slice-of-life from others is his psychological perceptiveness, as each panel, each angle serves a specific purpose. Enough said, see for yourself.
EDIT:
I almost forgot to mention
Iris Zero by
PRO Shiki/
HOTARU Takana. It's not an immediate slice-of-life title, rather a slice-of-high-school-life series, but it could still count. I figured you might like it because of its dark psychological undercurrent - and its highly perceptive protagonist. He's in the position of an underdog and chooses to play the role of an inconspicious loner, but his disadvantageous position only fuels his sharp deductive skills. Some mysterious happenings get slowly uncovered along with the background stories of his fellow students. One of the low-key treasures of the Shounen genre.
Last edited by Tripitaka at 6:34 am, Dec 5 2013________________
"Stories are what death thinks he puts an end to.
He can't understand that they end in him, but they don't end with him."
- Ursula K. Le Guin, GiftsTo be savoured:-
Blood Alone by TAKANO Masayuki
-
Otoyomegatari by MORI Kaoru
-
Gangsta. by Kohske
-
Seishun Kouryakuhon by AKIZUKI Sorata