Mega Man, known as Rockman (ロックマン Rokkuman, from the phrase "Rock 'n Roll") in Japan, also known as Mega or Rock in his original form, is the title character of what has been referred to as the "Classic" Mega Man series developed by Capcom since 1987. The pixel art for Mega Man was created by the designer of the original game in the series, Akira Kitamura (credited under the pseudonym "A.K"), and later turned into a refined illustration by Keiji Inafune. Since then, he has become one of the company's primary original characters and continues to be one of the video game industry's most recognizable icons. Having appeared on many gaming systems since the Nintendo Entertainment System, Mega Man has had a wide gaming audience, and his games continue to evolve with the ever-changing hardware demands of modern gaming systems. Mega Man's fictional universe can be divided into seven categories, each featuring different variations and incarnations of the same robotic boy hero. Although "Mega Man," or "Rockman," is usually the name used to describe only the original Mega Man from the classic series, it can also be used less specifically to describe the Mega Man series of fictional works, or the group of adherently named main characters within.