David Martinez is the protagonist of the series. He became a mercenary and a member of Maine's edgerunner crew in 2076 when he was involved in a series of harrowing events that resulted in him attaining the status of a Night City legend.
David was once a top student at the Arasaka Academy; however, he was ostracized and discriminated against due to his status as a member of a poor family. As a result of the tragedies, he faced including the death of his mother at the hands of the mobs, pursuing himself to become an edgerunner.
Background:
David Martinez was born to Gloria Martinez, who raised him by herself. His father is not mentioned in the series. David grew up on the streets of Santo Domingo. Due to his mother putting great effort into her job as an EMT, a cybernetic specialist, for the Night City health services, David was eligible for enrollment into the Arasaka Academy, a school with high prestige due to its location and students' social status. After joining the academy, David began selling XBDs, illegal braindance, to classmates that he obtained from a ripper doc and friend of his nicknamed Doc.
After he is hit with a personal tragedy, the death of his mother, he finds and installs a Sandevistan, a military-class cyberware, that was in his home in Santo Domingo. This leads him to run into Lucy, a young net runner who introduces him to the world of edgerunning and dreams of going to the moon. As the two starts to find meaning in their lives in each other, they also find themselves having to carve their paths through the violence and depravity of Night City to stay together.
Timeline:
At the start of the series, David is caught installing faulty software to his braindance to avoid paying for educational supplies. After having a meeting with the school principal upon David's violation, David and her mom, Gloria, heads back home.
While driving home, the two became bystanders in an attack, crashing into the vehicle after it was blown up by a rocket. The accident causes David's mom to get severely injured, and eventually pass away.
With no intention of going back to school after her mother's death, David implants the Sandevistan neuralware implant and starts his journey of becoming an edgerunner.
David uses his new implant on a job where he steals people's shards with a girl named Lucy. After spending all day with her, Lucy calls her team to confront David about his new Sandevistan, since Lucy's crew leader Maine ordered but didn't receive the Sandevistan.
After David explains his situation and his mother's death, he asks for a chance to repay the worth of Maine's Sandevistan by working with them. Even though the crew was hesitant, David's extreme tolerance for cyberware and personal determination makes him a member of Maine's crew, doing heists with others.
Over time, David develops an affection toward Lucy, and one day on Lucy's roof, they declare their love to each other and David promised Lucy to protect and help achieve her dream.
After the death of certain members of Maine's Crew after the Tanaka heist, David takes over the lead and continues the heists under the name of "David's Crew." Without the ex-members and Lucy's absence, David and his crew start to get famous and rank up as edgerunners.
Later on, David starts to experience mild cyberpsychosis, and starts to worry about his crew, Lucy, and doc. Even though many of his surroundings told him to downgrade and go light on chrome, David resists being okay.
David's crew gets caught in Faraday's trap which causes David to don the prototype cyberskeleton armor. After learning about the trap and the real story of the heist they signed up for, David and his crew face an entire army of Militech and Arasaka forces.
With the goal of saving Lucy, who was abducted by Faraday, David flies to the Arasaka Tower and kills Faraday, having his last moments with Lucy. Even though Lucy manages to get David to his senses after kissing him, it was too late for David since he already lost consciousness due to immense cyberpsychosis and overdose.
David goes into a final battle with Adam Smasher, sacrificing himself for Lucy's safety; he dies with contentment since Lucy was now able to achieve her dream.
Legacy:
After the final fight, Lucy fulfills her dream of making it to the moon and sees a vision of David similar to their first braindance experience together. She promptly laughs as she sees David and stares at the sky with sanguinity.