Nagato was a captain in Japan's Nation Self Defense Force. He was charged with monitoring Tony Stark from a distance, later being caught in the traffic jam Tony orchestrated for the Zodiac agents he was pursuing. He later caught up to Tony, demanding he cease his activity before being interrupted by the arrival of the agents in a hi-tech stealth tank. Nagato drove his own motorcycle into the tank, jumping off in the process to unveil its location, allowing Tony to attack it.
Later, he discussed the status of JSDF recon satellites with Minister Kuroda, claiming to have an idea on how to inspect the damaged Sat.3 directly. Conferring with Tony, he requested his help in ensuring Japan's safety using Iron Man. The two eventually initiated the plan, using a jet piloted by Nagato as the first part of a three stage rocket allowing Tony to reach the necessary altitude to combat Aquarius.
After two fighter jets are taken over by Zodiac's latest agent, Nagato asked Kuroda if now wasthe time to launch, only to be denied. However, as Tony returned, drained from his battle with Pisces, he was assailed by two duplicates of Cancer only to be saved by Nagato, clad in his Ramon Zero armour. He left the battle without saying a word to Tony.
After Tony and Chika's abduction, Nagato meets with Nanami to discuss the matter where he is given a lead thanks to Ichiro's photos. Flying out in the direction the yacht was last seen heading, Nagato caught sight of a flare fired by Tony, drawing him in, there, he had a brief confrontation with Scorpio before meeting up with Tony, finally revealing himself as Ramon Zero.
After dealing with the kidnapping, Nagato investigated the deaths of a Special Ops. Squad who had been securing a Zodiac Weapons cache. He was handed what's left of the data on a flash drive. He tracked the information to an orphanage, then eventually to Aki, a young girl currently staying with Tony Stark and requested that she be taken into JSDF custody. However, Tony refused, leading Nagato to take action. After securing the two, he explained the nature of Aki's ability to Tony, but before a decision is reached Virgo attacked their transport.
After being run off the road, Nagato and his men attempted to battle Zodiac's weapon, but their efforts prove futile, Nagato ordering his men back to headquarters. He later reappeared, attempting to cast the finishing blow after Aki crippled Virgo, but was interrupted by Tony, the two trading heated blows with one another. After Virgo got its second wind by combining with Aki, Nagato berated Tony for his decisions, pointing out the potential harm of letting it continue until it ran out of energy. This caused Tony to dive into the Magnetic field despite the danger.
Later, Nagato went intp the lab where his armour was stored, demanding answers as to what's going on there, only to be informed that his clearance had been revoked by Minister Kuroda. Meeting up with Tony, the two discussed their lack of leads on Zodiac before Tony received a call from Yinsen.
He rescued Tony after a disastrous fight with Yinsen and patched him up. The two headed back to the city, only to be set upon by Sagittarius. Sending Tony on ahead, Nagato endeavoured to hold Sagittarius off using an RPG launcher. After an unsuccessful battle with Sagittarius, Nagato was saved by Tony.
After Yinsen took control of Lab 23 and Minister Kuroda helped to resolve the situation, he called in Sakurai to detain Tony. Nagato took Tony to his own home where he challenged the American to a kendo duel with wooden swords, calling it a training course in the Japanese way of thinking. The two spar, both gaining the upper hand before calling it quits. When Zodiac announced its control over Japan, Nagato confronted Tony about their claim of being allied to him and questioning why they would say as much. Before he could get an answer however, Minister Kuroda called him and orders Nagato to execute Tony. Before he could make a decision on this matter, Tony escaped, leaving Sakurai wounded. Kuroda then reinstated him, ordering him to armour up and take Stark out.
The next time Nagato and Tony met, it was in armour. Battling in the air over the city, the two quickly crashed down in a baseball field where Tony refused to fight back. Reminding Nagato of what he had said about the Japanese way of thinking, the pair dodged just in time to avoid being attacked by the last of the Zodiac mechs, Gemini.
The two parted ways, Tony remaining behind to battle Gemini while Nagato searcheed for the source of the power drain from the Arc Reactor. Tracing it back to a hidden facility under Tokyo bay, he found Minister Kuroda and the final development of Zodiac, the Rasetsu armour. While he attempted to attack, he was quickly disarmed and thrown aside. In a last ditch effort, he fired a rocket, taking out the facility and forcing his battle with Kurodo into the air over the bay. However, the Rasetsu proved more powerful than Ramon Zero, breaking the smaller armour's sword before impaling Nagato and dropping him into the water below. Using the last of his strength, he contacted Tony and told him that Kuroda was behind it all before dying, his armour going dark at the bottom of Tokyo Bay.
Powers and Abilities
None, relies on armour
Experienced pilot: When asking for the best pilot the JSDF had, Tony got Nagato, implying he is the best pilot they have on staff, and he later claimed to be the best in the country. This likely added to why he would later pilot Japan's own Ramon Zero armour.
Strength enhanced by armour
Ramon Zero Armour: A more militant variation of the Iron Man armour, Ramon Zero is larger, more heavily armoured and seems to possess more weapons.
- Repulsors: While unconfirmed, Ramon Zero seems to possess Repulsors used for both propulsion and attacking, as shown when he destroyed a volley of rockets from Scorpio.
- Rockets: Stored in both forearms, Ramon Zero can launch rockets which pack enough force to blow the arm off one of Zodiac's Cancer mechs.
- Arm Blades: One of Ramon Zero's primary weapons, long, katar like blades stored in the forearms. They are sharp enough to cut cleanly through a Cancer mech and have the capacity to reflect energy attacks.
- Bladed Grapple lines: A retractable chain weapon stored at the hips of the Ramon Zero. It is a long length of chain with an anchor like piece at the end, seemingly designed for hooking on, but the outward edge is bladed, suggesting a multi-purpose function behind this weapon.
- Motorcycle: Nagato's primary method of transport when not in armour, he has replaced it at least once, having sacrificed it fighting a Zodiac Stealth Tank.
- Jet: When battling Aquarius, Nagato piloted a one man jet capable of reaching impressive altitude despite the strain on his own body.
- Sakurai had Level 5 clearance within the JSDF
- He is voiced by Jin Yamanoi in the Japanese dub and Travis Willingham in the English.