Issa Mihotoke, also known as Buccha, "Fats Buccha", "Black Pig", or "Fatty" (in the anime), is a member of Kogarasumaru specializing in close-quarters combat. Before joining Ikki's squad, he was the leader of the rival team, Yaooo!!.
Buccha is an inhumanly large young man with a build like a sumo wrestler. He is very tall, standing several heads above his teammates, with muscular arms and legs and an obese midsection. He is bald and has three distinct scars on his forehead. When using his 'Bump Up' ability, his limbs are further enlarged and his pot belly transforms into well-toned abs.
He wears headphones at all times, as well as his trademark pink-and-white striped shirt, green or blue slacks, and studded fingerless gloves. Because of his sheer size, he wears a specialized pair of four-wheeled ATs resembling miniature tanks.
Buccha was originally a bully and loved to toy with others and abuse his power. He was obsessed with becoming an ace Storm Rider, so he gained as many emblems as he could to prove his worth. After his loss to Ikki, he decided to start fresh and reform his attitude.
After joining Kogarasumaru, Buccha is much nicer and calmer. He's more friendly and values his teammates more than he did before. He can still be rather stubborn, and at one point thought about leaving the team should Ikki abuse his position or make decisions without consulting the other members. He does not give respect or trust freely, but if someone impresses him enough, he is willing to open up to others.
Buccha loves to eat and his go-to dish is ramen. However, his rotund appearance and constant preoccupation with food belies the fact that he is actually a superb athlete. In fact, his body is only ten percent fat, and his excessive caloric intake only serves to further enhance his abilities. He generally dislikes losing weight.
Buccha is the son of a Buddhist monk, and is in a relationship with Kyo, the sister of Orihara Masaya. He originally appeared in the series as a villain, the leader of the team Yaooo!!. He and his squad dominated Higashi Junior High by night, earning them the nickname "Night Kings".
After losing against Ikki in a Hurdles match, Buccha pledges allegiance to him and becomes a founding member of Kogarasumaru. He once threatened to leave the group due to Ikki wanting to merge with Genesis, stating that was not the decision of a good leader. However, Ikki proved his worth to Buccha again and he decides to stay. When Ikki and Agito were in the hospital for their injuries, Buccha and the others had to fight the other teams, challenging them to rank up to a Rank C team. When Kazu was declared the replacement leader by Ikki, Buccha stated that Ikki made the right choice and encouraged Kazu to believe in himself for the battles at hand.
After Sora's betrayal of Genesis, Buccha and the allies of Kogarasumaru arrived at their headquarters to fight Genesis and save Rika. On the aircraft charrier, he was matched against Orca in the main ballast tank of the vessel. In an intense underwater race, Buccha's wrists were cut in an attempt to drain him of his blood. He eventually wins by inhaling and exhaling water rapidly to propel himself downward, then slamming Orca to the ocean floor. After the match, Orca joins Kogarasumaru and Buccha sees Ikki off to fight Sora in the final battle.
Since Orca's heel-face turn, Buccha has seemed to develop a bond with him, as is shown in the aftermath of the battle on the aircraft carrier, and in the afterward with Orca riding on his shoulder.
Buccha is a 'power' type rider specializing in close-quarters combat. Despite his heavyset appearance, he actually has a well-toned, muscular physique. His apparent obesity is caused by a large amount of blood pooling in his gut from overeating. With the use of his 'Bump Up' ability, he redirects his blood flow to his muscles, revealing and enhancing his true figure. This technique grants him greatly increased strength and reach, making him a tremendous threat against most opponents. His 'shadow' is a tank, signifying his ability to body-slam opponents with the force of a cannon shell.
Although Buccha has the skills to potentially rival a King, he initially lacked the mental will to utilize them fully in battle. Since joining Ikki's crew, he has undergone mental training with his father to strengthen his focus and improve his self-confidence. As demonstrated in the battle with Sleipnire, his body can withstand huge shock waves like those made by Ikki, Kazu, and Agito. Spitfire observed that the attacks were so strong that only a mountain could withstand them, branding Buccha, "The King of Mountains".
In his battle against Orca, Buccha utilizes a more concentrated, "Zen" fighting style. Rather than using 'Bump Up' to restructure his upper body like usual, he instead focuses his blood flow to his lower body, allowing him to move at higher speeds then he'd ever been capable of before. He dubs this technique, "Buccha High Speed Light Tank Mode".
Buccha's road is The Rock Road. He is able to create and emit powerful vibrations from his body. It is also revealed that, because his body contains ten times the amount of blood of a normal human, a huge amount of oxygen stored in his hemoglobins effectively make his blood function as an oxygen tank. As a result, he can hold his breath for over twenty minutes.
During the fight between Sleipnire and Kogarasumaru, Buccha had a battle level of 68.
- Buccha's name and character design are homages to retired professional wrestler, Abdullah the Butcher.
- Bump Up: Buccha transfers all the blood in his upper body to his muscles.
- Back Spin Wallride 360°: Buccha performs a reverse spinning wall ride.
- To That Grab to Fake Spin Accelerator Buccha Special 1440°
- Spinning Wallride Overbank 1800° Buccha Special
- To Moonsault 900°
- Buccha Backward Accelerator Wallride 360°
- (With Ikki) Buccha Tornado: Ikki uses Pile Tornado to propel Buccha at high speeds towards the enemy
- Bump Up Reversal: Buccha uses Bump Up on his lower body, effectively increasing his speed and the strength of his legs. This also allows him to enter High Speed Light Tank Mode.
- Hammerhead Death: Buccha launches himself off of a wall torwards his opponent.
- Enlightenment Pump Up V3: Buccha pumps up the blood from his body to his arms. And uses the iron in his blood to increase his diving ability.
- Buccha Snowplow: Using the hands as a plow, pushing and pulling motion, diving underwater, it adds up to the acceleration due to that the weight now will be centered upon the palms.
- High Speed Light Tank Mode: This form allows Buccha to move faster that normal, in order to enter this mode he must first use Bump Up Reversal.