I have not read the manga, so my comments are all about the series.
It's a heart-breaking, delightfully heart-warming experience.

Pros
The cases are unique in themselves. Mostly heart-breaking and sad. The retelling of the cases and their progression are a delight to watch. Don't expect a hard-core, very difficult case. It's all about the human-ness of both the villains and the victims.
Totono is adorable, he embraces his life fully. He possesses a unique insight into each character that he meets. Not surprisingly, he's drawn to people like himself: people without artifice, people who take their lives in their own hands and live it the way they want to.

Cons
The scene flashbacks could be lesser.

Rewatch value:
Absolutely will watch it again.