The plot follows a dark humor comedy on the infamous murderer silhouette of every murderer 'Hannzawa-san' in DC/MTC universe as it is planning to murder someone (without mentioning who) starting with moving out to Beika city where many murders take place everyday. The manga seems like it's making fun of DC/MTC universe by poking out odd things the series oversees in order to adapt the setting to the plot.
Why would you read it?
You're either a DC/MTC fan who's thrilled to see small cameos of the cast and of characters that haven't been out there for a while but are unforgettable, crime scenes from the series
and you have always wondered what is the secret life of the murderer silhouette. You will enjoy it's creepy grins and frightening laughs.
Or you like to read all kinds of original stories!
You have to know that 'Hannzawa-san' is a murderer that thinks of committing a murder every time he gets in a situation by imagining it.