He is your older brother Jay.

Weight 95 kg, height 195 cm, 17 years old, Navy instructor

Hell's Dance's Perfect Dodge He moves so fast with his legs that he leaves behind afterimages that can be easily damaged, causing enemies to hit empty space.

Physical strength and destruction: Jay can easily break granite blocks weighing over 100 kg with his bare hands.

Code of Honor: He initially appears as an exchange student from the United States and acts as the protagonist's rival. However, even as an opponent, Jay behaves with exceptional honor and fairness, rejecting any dirty tricks.

Cool-headedness and composure Unlike many hot-tempered students of the school, Jay knows how to remain absolutely calm; it is extremely difficult to anger him with mockery or provocation during a fight.

He's incredibly dedicated to his dream of becoming a great boxer like his father. In battle, he relies on incredible willpower and is prepared to fight to the bitter end.

Devotion of friends: Quickly imbued with respect for the students of Otokozuku, Jay officially enrolls in this school and becomes one of the most reliable and loyal comrades for the main characters, ready to risk his life for the team.
General information about Jam's name is Jay, and his name is King Baler Jr.
Origin: US: Former US Naval Academy cadet
Stas is a first-year student at Otokojuku Academy. He specializes in heavyweight boxing and is a master of ultra-sonic blasts.

Appearance and Style: Jay has the classic look of an American action hero from the 1980s. He is a tall, athletic man with a muscular build, short, crew-cut hair, a military-style crew cut, a strong, powerful chin, thick eyebrows, and a stern gaze. His expression is almost always one of absolute concentration. Outside of his formal school uniform, he often wears elements of American sports or military gear.

Speed ​​and reflexes are key to breaking the sound barrier; his hand speed is incredible. Jay's basic technique, Mach Punch, is a punch that officially breaks the sound barrier. The sonic wave he creates is capable of inflicting damage at range, similar to the Jet Sonic Mach Punch technique.
The incredible frequency of his ultimate combo, Flash Pisto Mach Punch, allows him to deliver 10 to 16 supersonic blasts per second, completely rendering the opponent unable to dodge or block the attack.