Sangatsu No Lion is a good manga that is less talked about than many others that it is superior to .
Perhaps it's because of its synopsis which fails at being eye-catching .In any case this is not bad or boring provided you don't dislike slice of life .
On to the review then .
Story - 7
Being slice of life in its purest form ,Sangatsu No Lion doesn't exactly have what you can call a major plot line .This is just the story of a high school shogi pro with family issues .Like a biography ,you cannot exactly pick a point that represents the story even if it's the ending .That doesn't mean the content is poor or scanty however as his life and troubles are portrayed in a realistic and interesting manner .The score for this aspect of the manga could be seen as higher by some though I think 7 is the lowest possible score it should be given since it isn't plot driven .Calling it a 9 would not be something I say is incomprehensible though .
Art - 7
Another difficult part to judge .The art might be seen by some as rough and not very neat while others might see it as good for the story's presentation .Sangatsu No Lion's drawings are not terrible though calling them excellent seems to be a stretch .In any case this is one of those things you have to see for yourself to judge and as it depends on your preferences I cannot but give it a score of 7 in relation to other manga .
Character - 8
This is the manga's strong point .Being a drama SoL it depicts it's characters realistically .No plainly drab or boring characters to spoil the appeal of the series ,no ridiculously unbelievable characters to ruin it either .It does what it does well and that is enough .The MC especially is well fleshed out and can be understood .Some characters might be seen as slightly unrealistic by some but I don't think it affects the quality if this work .
Enjoyment - 8
In terms of enjoyment I'd give this an 8 .It's a good read especially if you enjoy slice of life .To be honest this kind of manga isn't what I usually read and so I'm quite impressed by it .Don't worry about the synopsis and read it .
Overall - 8
The above ratings might put you off but I think this is a manga that can essentially be seen as greater than the sum of its parts .Drama/SoL lovers should like this especially .