Monster Maezuka is the former stage name of Atsushi Maezuka, a Japanese voice actor born on March 19, 1962, in Osaka, Japan. He is a graduate of the Osaka University of Arts, where he studied broadcasting. Throughout his career, he has been affiliated with several talent agencies, including the Osaka Television Talent Bureau, Clutch, and later S·I·P, to which he moved in 2007 when he began using his real name professionally.

Maezuka is best known for his extensive and long-standing work with the video game company SNK, particularly in its fighting game franchises. He has provided the Japanese voices for multiple iconic characters over several decades. His most prominent and enduring role is that of Benimaru Nikaido in The King of Fighters series, a character he has voiced continuously from the series' debut in 1994 with The King of Fighters '94 through the latest installment, The King of Fighters XV, released in 2022. This makes him one of the few voice actors to have maintained a role in the series for its entire history. In addition to Benimaru Nikaido, he is also the original voice for fellow Ikari Warriors team member Ralf Jones and the diminutive assassin Choi Bounge in the same series.

His collaboration with SNK extends to its other major fighting game properties. In the Samurai Shodown series, he voices the flamboyant kabuki performer Kyoshiro Senryo, a role he has also played for many years, including in the 2019 reboot of the series. He has also voiced the character Nicotine Caffeine in the same franchise. In crossover titles, he has taken on roles such as Ken Masters in SNK vs. Capcom: SVC Chaos.

While primarily known for video games, Maezuka's voice work includes roles in animation, directly confirming the examples provided. He voiced Ralf Jones in the 2006 anime OVA series The King of Fighters: Another Day. He also contributed to the original Japanese version of the anime Chō Seimeitai Transformers: Beast Wars Neo, providing the voice for the character Sling as well as serving as the series' narrator. Other anime roles include Zeus Asamiya in the long-running series Bleach.

A notable aspect of Maezuka's career is his enduring association with the characters he originated. He is recognized for his consistent performances, having voiced characters like Benimaru Nikaido and Kyoshiro Senryo across multiple generations of gaming hardware and series reboots for nearly three decades. His contributions to the sound of SNK's game universes are a significant part of his professional legacy.