There was a time when there were lots of cases with 4 suspects, I guess you can say Gosho is somehow going back to the basics with this case : 4 suspects, a client, some blood...This case just feels like the good old ones to me.
The plot section is three lines long; I read it and I don't think it spoils the movie that much, most of the information was already given in the trailer. Besides, why go on the movie 15 page in the first place if you don't want to be spoiled ?