the score (7) is based on everything + enjoyment factor while with all above stuff now i know that you might be thinking that you must give it 10 nah but not, giving reason are :
1.It is a manga and in manga more of the flow must be depicted through the pictures it is a novel adaptation so i think that as a reader wound up betwwen picture and conversational aspect , depth of story and emotions are outright but this doesn't fit the genre of manga original novel or a movie may do a better work with the script.
2. again conversation/narration length is to long that is not fit for manga.
3. use of heavy words to shorten the length of sentences these were able to depict in conscience of what they talk in 30 minutes but takes me sometimes 3-4 to re read it to get sentences were not enough to express whole feeling ,takes time to connect to character therefore decrease tne pleasure of reading.
these are the reasons why i was unable to percieve story as i should be, in depth as well in contrast of characters
and giving it above 5 the description is as follows:-
1.)This manga basically deals with the story of two persons one who have comitted 3 murders and is a death row inmate, and a retired pianist who have failed suicide three times(Trivia:- see how '3' is a common factor :)) and how they come to understand each other heart and understand meaning of life it talks about there perspective towards life before and , during and after meeting each other. So from the onset itself you can guess this is gonna be a heart wrenching story.
2.)It is a highly descriptive manga talk about complexeness of human relationship and hardship it also beautifully establish a sense of sympathy towards the characters ,I was personally drawn towards the female character who come to understand life and overcome her hardship by enjoying the small happiness of world around her , her character is beautifully potrayed while regarding male charcter it is beautiful to see how he his transformation occurs from a isolated man to a comlete different personality.
3.)It is beautiful to see how love blooms in a prison between two person who being alone and different , are not so different from each other .Also the points above points must also considered as critsism as they drawback such beautiful story and characters.
4.)If you are tired of generic romance you may enjoy it.
And If you want to enjoy it read novel version that is translated or watch a good movie based on it, for avid readers with good language grasp in literature reading manga may do the trick.