Masamichi Yokoyama was a Japanese manga artist and original creator born on April 29, 1930, in Nagoya City, Aichi Prefecture. He began his career in 1952 while attending Meiji University, initially working in the rental library manga market with a work titled Sakuragai Hime. By 1956, he had transitioned to publishing in magazines, establishing a long and prolific career that spanned multiple genres and formats. Yokoyama passed away on October 14, 2003, at the age of 73.

Yokoyama’s body of work is notable for its remarkable diversity, encompassing historical epics, war stories, non-fiction, hard-boiled dramas, and comedies. Among his significant historical manga are Taiheiki, Sanada Yukimura, Sakamoto Ryoma, and Saigo Takamori, reflecting a sustained interest in Japanese history and notable figures. He also worked as the original writer for other artists, such as on the manga Ooku Kasuganotsubone, which was illustrated by Mitsugu Saotome.

He was also a prominent creator of adult-oriented comedies, a genre in which he achieved considerable popularity. During the 1970s, his erotic comedy series serialized in publications such as Nikkan Gendai gained a strong following among Japanese office workers. A notable example of this phase of his career is Yaruki Manman, a manga serialized in 1977. This work was later adapted into an anime, confirming Yokoyama’s role as an original creator whose material was adapted for the screen. The anime Ageman to Fukuchin stands as another example of his work being adapted into animation.

Throughout his career, Yokoyama operated a production studio, Yokoyama Pro, which employed several assistants, including Baron Yoshimoto, Shuuichi Seino, Junji Kanzaki, Eiko Fujiwara, and Yakuyuki Tagawa. Many of his manga, particularly during the 1970s, were created in collaboration with this studio and often involved partnerships with various writers who provided the original story concepts, such as Toshiyuki Kajiyama, Chiho Katsura, and Ikkou Shimizu.

Yokoyama’s industry significance lies in his versatility and longevity, moving fluidly between literary historical fiction for adults and broadly appealing erotic comedies for a popular audience. His work continued to be republished after his death, including complete editions of series like My Tea Jack, demonstrating the enduring presence of his extensive catalog in the Japanese manga landscape.