The defining voice of the Ippo franchise, the ring announcer is with us throughout every liver blow, gazelle punch, and Dempsey roll of every match. His approach to color commentating makes Howard Cosell look like Max Kellerman and is often more enthusiastic and aggressive than the fighters in the ring. He is unrivaled on the mic and unbiased toward the fights, refusing to shy away from controversial criticisms and insisting on calling it how he sees it. Many life lessons can be learned from this great man, whose mysterious past, or even name may never be revealed.

Makunouchi Ippo has been bullied his entire life. Constantly running errands and being beaten up by his classmates, Ippo has always dreamed of changing himself, but never has the passion to act upon it. One day, in the midst of yet another bullying, Ippo is saved by Takamura Mamoru, who happens to be a boxer. Ippo faints from his injuries and is brought to the Kamogawa boxing gym to recover. As he regains consciousness, he is awed and amazed at his new surroundings in the gym, though lacks confidence to attempt anything. Takamura places a photo of Ippo's classmate on a punching bag and forces him to punch it. It is only then that Ippo feels something stir inside him and eventually asks Takamura to train him in boxing. Thinking that Ippo does not have what it takes, Takamura gives him a task deemed impossible and gives him a one week time limit. With a sudden desire to get stronger, for himself and his hard working mother, Ippo trains relentlessly to accomplish the task within the time limit. Thus Ippo's journey to the top of the boxing world begins.

He is known for playing tough or grouchy men in dubbed anime and video games. His career includes Hotohori in Fushigi Yūgi and Jin in Samurai Champloo. He also played numerous cameos and minor characters in Rurouni Kenshin, in addition to the major character of Hajime Saito. He also does Don Patch in Bobobo-bo Bo-bobo as well as Gabumon and other voices in Digimon.  According to Anime News Network, Thornton has the most credits of any male voice actor and he is second in total voice actor credits only next to Wendee Lee. He has been in nearly two hundred voice-over productions for Japanese animation.  Thornton is also well-known for having played many different minor voice roles throughout the Power Rangers franchise (and similar series such as VR Troopers and Masked Rider).  Thornton has also had experience with ADR direction. Currently, he is co-directing the ADR for the popular anime series Bleach alongside Wendee Lee.

His name is sometimes mistranslated as Hitoshi Horikawa.

Makunouchi Ippo has been bullied his entire life. Constantly running errands and being beaten up by his classmates, Ippo has always dreamed of changing himself, but never has the passion to act upon it. One day, in the midst of yet another bullying, Ippo is saved by Takamura Mamoru, who happens to be a boxer. Ippo faints from his injuries and is brought to Takamura boxing gym to recover. As he regains consciousness, he is awed and amazed at his new surroundings in the gym, though lacks confidence to attempt anything. Takamura places a photo of Ippo&rsquo;s classmate on a punching bag and forces him to punch it. It is only then that Ippo feels something stir inside him and eventually asks Takamura to train him in boxing. Thinking that Ippo does not have what it takes, Takamura gives him a task deemed impossible and gives him a one week time limit. With a sudden desire to get stronger, for himself and his hard working mother, Ippo trains relentlessly to accomplish the task within the time limit. Thus Ippo&rsquo;s journey to the top of the boxing world begins. 
(Source: MAL Rewrite)

Ippo Makunouchi continues his boxing career and his goal on knowing the meaning of being strong, and the desire on fighting his idol Ichiro Miyata once again. Along him are pro boxers Takamura, Aoki and Kimura that each one of them aspire to their own dreams.
 
(Source: Anime News Network)

As the new Champion, Ippo must protect his title against some of the best boxers available. 
Makunouchi Ippo is the new Featherweight champion of Japan and is now ready for his first title defense. His opponent, the former Jr. Featherweight champion and a medical student, Sanada Kazuki. In addition to this feud, Sanada is being coached by Kamogawa's former rival, Hama Dankichi. What makes things worse is that Sanada works at the same hospital where Kumi is a nurse at and everybody at the hospital wants Sanada to win. Not only does Ippo have to defend his title, he has to reclaim his love.
 
(Source: Anime News Network)

Kimura finally has his championship match. It takes place at the annual champion carnival. But now he must face the intense champion, Mashiba for the Junior Lightweight championship.
 
(Source: Anime News Network)

Jikkyou Announcer