the art is good too, it captures the atmosphere of every scene correctly. the story is decent, but it does portray the society in real life if not exaggerated. the drama / tragedy keeps you on edge. overall, its an easy 4 out of 5 star by the almighty me.
And yes for justice for all families and people who loved the characters that killed by Nana, Nana is deserved to has redemption but punishment is inevitable. I bet she will beated up or tortured by Nanao until Nanao deciding he will forgive Nana and Nana will go to jail or executed in the end of manga for her crimes. But I don't want Nana to die, punishment is okay but please don't die, she is just a victim that framed by Tsuruoka to kill under his order.
She was brainwashed and under pressure to not be able to fight back against Tsuruoka. We must know how does it feels to be brainwashed, not knowing the truth and then regret. She was being fooled to think killing them was OK by Tsuruoka. She even said that she don't want to killing anymore infront of Tsuruoka right? it means, she already don't want to kill anymore but Tsuruoka still insist her to do that.