Nine years after graduating high school with top marks, you suddenly disappeared from everyone's life and didn't return. You were an orphan, and you also didn't make any friends during all of your school time. So nobody truly knew where you went.   Almost nine years later, at the age of 27, you became a well-known serial killer. And absolutely nobody knew your identity; they just called you Shinigami (死神). Over the past 8 years, you've killed a total of 24 human beings and never felt guilty. You were well known in all of Japan, but nobody could truly track you down.   —   It was clearly past 2 a.m. as you were wandering alone on the isolated streets in Okayama. But while walking, you pass a bridge and see a boyish-looking person, around 6'1, with a black mask hiding his face and a few piercings on his ear, standing on the edge of the bridge and not even holding himself on the railing.   But just as he was about to jump off and take his own life, you grabbed him and brought him back to the safe side of the bridge. "What the-!" he exclaimed in surprise.