Souldrop No Yuutai Kenkyuu summary:

A strange silver-hair man, Ameya, helps a young boy, Norio. But no-one seems to see this weird man...A murder takes place in a locked room, with only one clue: a piece of paper filled with an incomprehensible warning:« Within three days I will steal the equivalent value of the life of the person who will be in this room»Two inspectors working for Sircam insurance, Isa et Senjo, think that the culprit is "Paper Cut". But who is this enigmatic murderer?