Martínez is a well-built black man who is said to be almost two meters tall. In official illustrations he is bald despite being described as having a buzzcut in the novels, and has tattoos on both his arms. His usual attire consists of a dark coloured tank top and pants, as well as sandals. He occassionally wears a black leather jacket.
Light Novel Volume 1Edit
Martínez is introduced when he is working with Jiro to dole out punishment to Shota Yamazaki, for torturing and killing cats. He gives Yamazaki the same brutal treatment he inflicted on the cats until he eventually decapitates him. His next job is to deal with Saitoh, however at that moment, Jiro receives a phone call from Yamato asking him to take revenge on Lin for punching him. Martínez agrees to take on the job in Jiro’s place.
He eventually confronts Lin and punches him in the stomach. Lin believes Martínez to be a killer sent by Zhang, but Martínez reveals that he was only hired to deliver that punch on behalf of Yamato, then hands Lin his business card.
Some time later, after Yusuke is captured and forced to admit his crimes on camera, Martínez is hired to torture him. Since Yusuke had committed rape and murder, Martínez intends to inflict the same upon him.
Light Novel Volume 2Edit
Martínez meets Enokida at a cafe and asks him to help locate the driver of a vehicle involved in a traffic accident. He reveals that he is trying to find this person on Jiro’s behalf, since he is busy and Martínez could use the work. Hearing this, Enokida puts an ad on undergroundjobs.com advertising Martínez’s services.
After Lin, who is disguised as the Niwaka Samurai, is captured by Abe and Yamamoto, Martínez is hired to torture him. Having received a photo of who he is to torture from his clients, he realises it is Lin and has Saeki and Jiro prepare a dead body made to look like Lin. Upon his arrival, Martínez requests that he be alone while he tortures Lin, then helps him escape by mutilating the body he bought with him and putting Lin into a suitcase. Before leaving, he tells Abe and Yamamoto that Lin is a friend of the Niwaka Samurai.
When they make it out of the building, Martínez notices Abe and Yamamoto’s van and attaches a red back spider model listening device to it. This later allows him to locate them.
When Jiro and Misaki work on capturing Abe and Yamamoto for an avenging job, Yamamoto manages to escape but he is stopped when Martínez hits his van from behind with his SUV. To Jiro’s surprise, Martinez reveals that these were the culprits behind the hit and run they were investigating.