Samart Sirinto (サーマート・シリントゥ) is a 7-time Muay Thai Champion and is called the strongest middle weight man in the world. He has been selected as Muay Thai strongest fighter for three years in a row. Samart was also formerly the K.O.S. middle weight champion
Light brown tanned skin-tone/Brown hair
Very honorable and caring man. He is also very polite. Due to his strength and Satoru's cerebral arteriovenous malformation (congenital brain disorder) - which led to his death -, Samart fears his own strength. Because of this, Samart goes to extreme lengths to make sure that he does not endanger his opponents life (he holds back to win by decision every time/tries to minimize the damage to the opponents head). He can also be said to have found a new respect for life after the incident. Because of the incident, he also does not care if he has to forfeit a match to protect his opponent as demonstrated in chapter 294, during the Raptors World Championship, when he just left the ring while his adversary stood there with confusion and humiliation.
Sirinto is refereed to as a genius, who did the Raja's Champion in beyond recovery when he was at the age of 16. It has been said since then betting on him was useless, as the "monster" was banished from nearly all the stadiums (due to his overwhelming strength). After that, he made a living fighting fighters many levels above him and even heavyweight class fighters in America and The Netherlands, but still hasn't lost once. Three years ago from chp. 98 's timeline, Samart was cast in an opener bout for K.O.S. . His opponent was Kaburagi-ryu National Middle Weight Champion Ibuki Satoru. Even though Satoru was strong enough to beat Mutou to a pulp, Samart barely broke a sweat demolishing the Kaburagi-ryu middle weight champion. In the second round Samart connected with a left hook to Satoru's face. Followed by a left middle kick to his foes ribs. Satoru realized with enough speed he could sneak inside and drive an uppercut right into Sirinto's thin jaw. Once the plan's in motion, Samart throws a left straight, but Sirinto dodges it. As Satoru throws a left uppercut- coming within inches of Sirinto's chin-scraping his left onto the left side of the Thai man's cheek , Samart knee (left knee) kicks Satoru in the chin. This "monster's" incredible and seemingly effortless tenkao (knee kick) matched the timing of Satoru's left uppercut, meaning he almost basically avoided it at the same as he attacked. His knee's explosive power knock Ibuki out and and triggered the blood vessels in the affected area to fail thus causing a hemorrhage in the brain to occur, leading to his death (several days later) . Samart visits Satoru the day after he dies and expresses remorse . His trainer and long time mentor () tells him the fault lies with the sponsor for casting a bout with too much of a strength difference and that he did nothing wrong. Still Sirinto is grief-stricken as he walks past Mifuyu. She asks him if Satoru was strong. Sirinto say that not too many fighters that could injure his head, and that if their match had been several year later the result might've been reversed. Mifuyu thanks Samart and says Satoru would've been happy to hear that. She then apologizes as she says she will resent Samart for the rest of her life( not only was Satoru taken away from her but so was her/Satoru's unborn child which miscarried due to excessive mental stress brought on by see Satoru go down in the fight).
Due to this incident/accident, Samart develops a fear of his strength, a fear over death, and newfound respect for life. He vows to never have an accident like that again. Samart t begins to demonstrate high levels of compassion towards his adversaries, as he does not injure what cannot be healed (attacks legs, arms, and torso) and tries to restrict damage to the head. Samart goes on to become 7 time champion in Thailand while also becoming K.O.S. Middle Weight Champion. In chapter 274, Samart is scheduled to fight in the Raptors World Championship against Hamada Kaoru. The day of the K.O.S. Raptors while Samart is in his waiting room, Simizu Ryouji (TV producer) asks for an agressive fight with spectacular KO's. Samart politely declines as he tells Shimizu his philosophy towards fighting- which is to win not to injure. Samart was also formerly the K.O.S. middle weight champion, before he forfeited the Raptors World Championship bout with Hamada Kaouru (even though Samart was basically taking it easy on him and handling Kaouru like a child and it was pretty clear that Hamada wouldn't win at all) . Ending with Hamada's embarrassment from not being able to compete with him at all and Director Izumi permanently banning Sirinto from K.O.S. .
Before his fight against Satoru, Samart viewed dying in the right as the most honorable death for a fighter. However, after Satoru died, Samart changed his view. He thought that as he can't know what a dead person wishes he should contain himself to cause the least damage it takes to win the fight.
In Satoru's fight, Sadam says that "Samart did the Raja's Champion in beyond recovery when he was 16. After that, he was banned from nearly all stadiums as betting against him was pointless."
Sadam also said that Samart had been making a living by fighting against fighters of many levels above him in America and the Netherlands, including heavy weight classes. And still, Samart didn't even lose once.