This is Dieter, one of the protagonists from the Doujinshi: Kansai Jin to Hukumen Satsujinki
for his first appearance use: dieter, 1boy, solo, sack mask, tall, muscular, white shirt, black necktie, black pants
for his second appearance use: dieter, 1boy, solo, lifted up sack mask, tall, brown hair, medium hair, goatee, facial hair, tall, muscular, white shirt, black necktie, black pants