Hayato Jin is one of the main protagonists of Getter Robo Devolution. He is a former revolutionist who strove to take apart the reigning government slowly but surely. He is later recruited to fight the Devolved when he catches a glimpse of what really goes around beneath plain sight.
Hayato resembles his original counterpart, a young man with black hair combed straight covering part of his face. He has piercing eyes with black pupils and almost always has a cold look.
Hayato is a stern teenager, wishing to break through the veil of what he views as a fake existence. As such he strives to tear apart the government powers through an economic invasion by manipulating the stock market and later start a war. He is very violent, willing to go to extreme measures to make sure no stands in his way. However, after meeting Dr. Saotome, witnessing the Getter Robo and the Devolved, Hayato changed his goal to fight the monsters in order to truly understand the newly revealed reality. He is still rather antisocial and critical, acting rather antagonistic with his teammates, especially Ryoma.
Hayato is highly intelligent, able to surmise and predict events related to business, politics, and physics; allowing him to do things such as control the stock market to get funding. He is a swift and powerful combatant; able to fight, injure, and subdue armed guards on his own. After going through the training sessions, Hayato has managed to get control and effectively pilot a Getter Machine. Having never gone through any sort of combat training, Hayato gets into fights with Ryoma to better himself while also being critical of how he fights.
Hayato and his posse had managed to use the stock market that caused some businesses to close down while obtaining the money. He is later visited by Dr. Saotome and armed men. When asked what his goals were, Hayato revealed his intentions to start a war. Dr. Saotome saw this as foolish and revealed his intentions to bring Hayato with him having the guards draw their weapons only for Hayato to overpower them. Saotome however tranquilized Hayato and brought him to his facility. There Hayato reveals his desire to bring about the truth of the world by toppling over political figures. While Saotome sympathizes with him, he then reveals the Getter Robo and news about the real truth behind the world. This gets Hayato's attention and he joins Saotome in the battle against the Devolved.
When the first monster attacks, Hayato is not amused by the recruitment of Ryoma Nagare and just tells him to show the team what he's got. After the battle, Hayato formally meets Ryoma. When Ryoma brings up the many questions including how Dr. Saotome does not seem to mind about the casualties at Ryoma's school, Hayato brings up how Ryoma did not seem to mind himself. By the time Ryoma left with Dr. Saotome to the Saotome Institute's secret area, Hayato ponders if Ryoma will be useful.
By the time the battle was over and Ryoma started asking question about the morality of the institute, Hayato called out Ryoma's own wild behavior in battle until Ryoma sees the Institute's secrets. When out gathering sample of the Deformed as they latched onto the bodies of some the Institute staff, Hayato killed a group of them with the Getter telling Ryoma to take a good look at the threat they face and what they are capable of. Back at the labs, Hayato speaks with Dr. Saotome about the nature of the Devolved Beings while meeting a mysterious man that stuns him.
In battle with another Devolved Being, Hayato calls Ryoma out for not changing to Getter 2 which lead to the monster escaping. Back at the base, Hayato brings up Ryoma past calling him pathetic causing a fight to break out between them. Despite his lack of combat experience, Hayato knocks Ryoma down noticing that Ryoma's past traumas are still affecting him. Hayato calls out that Ryoma is not giving his all, and that he is crying on the inside keeping him from going all out.