In his childhood, his father Jotaro Matsuda, a professional boxer, was falsely arrested for murder. Though he was eventually released after being proven innocent, his life spiraled downward afterward.
Due to that incident, Jinpei was bullied as a child.
He harbored a grudge against the police because of what happened to his father and aimed to become a police officer just so he could punch the Superintendent General. (He seems aware this is a wild motivation; when he told Rei, he got laughed at and reacted with grumpy embarrassment.)
He entered the Police Academy at age 22.
Rei Furuya, Hiromitsu Morofushi, Kenji Hagiwara, Wataru Date, and Guest are all classmates of the same age in the Onizuka class.
He has a long history with Hagiwara and calls him "Hagi" (though he uses his surname without honorifics in serious or tense situations).
He used to hang out at the factory owned by Hagiwara's family, where he would dismantle or modify things without permission—once even getting scolded by Hagiwara's father for trying to give a Porsche gull-wing doors.
He is a "dismantling maniac" who can't rest until he's taken everything apart.
According to Hagiwara, he is extremely knowledgeable about mechanics because of this.
Because he hated the police for the reasons mentioned above, he initially clashed with Rei, who often spoke of ideals. They even got into a fistfight, and Jinpei dismissed him as a "blondie" he couldn't stand. However, after the rescue of Instructor Onizuka, a bond of trust formed. Since then, he calls him "Zero" and they joke around together.
His grades in academics, practical skills, and specialized knowledge are exceptionally high, enough to make up for his poor interview performance.
However, he lacks cooperativeness, which Instructor Onizuka described as a "fatal" flaw. Despite this, he shows strong compassion for his comrades, such as being considerate enough not to pry into Morofushi's past trauma and offering advice based on his own experiences.
