Juror 13 manga

With the arrival of a mysterious jury summons, a man's life is thrust into a dizzying downward spiral: his fiancee leaves him, he has problems at work, and his best friend is suddenly nowhere to be found. As the jury trial approaches, who can he trust? Why does he suddenly feel that he has to defend his every move? And who exactly is Juror 13? Can he trust what he sees?