In Tokyo revengers, the protagonist Takemichi Hanagaki can time travel, the first time he does time travel is on July 4, 2017, when he falls onto the tracks and was going to get hit by the train, at that moment he thinks of Hinata Tachibana and his memories of his middle school days and then when he opens his eyes, he finds himself in a train, then he later comes to know that the date was July 4, 2005, and that he has traveled 12 years in the past.
How many years did Takemichi Time Travel?
He then realizes that he can time travel and his switch to time travel was Naoto Tachibana, whenever they shake hands Hanagaki would travel through time 12 years from the present date i.e., if the present date is July 8 2017 and he shakes his hand with Naoto then he would go back in time by 12 years to July 8, 2005.
Their purpose in the past was to perform actions so that they could avoid the death of Hinata Tachibana, who died due to a brawl between two gangs. Naoto wanted to save the life of her sister, Takemichi first shared this same purpose with him but slowly-slowly he comes with a new purpose that is to save everyone.
During the time of the time travel his present body stayed in the state of comma and whatever changes his actions caused in the past would affect the present and it would be only known and remembered by him and Naoto.
How Takemichi can Travel?
There was also a condition that was to be fulfilled for Takemichi to travel through time and that condition was both Takemichi’s and Naoto’s purpose must align for him to time travel, if one of them felt satisfied with the present period then takemichi won’t be able to time travel. There occurs a certain situation where takemichi wants to go to the past to change something and he forces Naoto to shake hands with him but still he could not go back as Naoto had fulfilled his purpose of saving his sister and the other condition was it was Naoto needed to stay alive while shaking the hands otherwise Takemichi would fail to go the past.
The problem with his time travel was that he can travel only 12 years in the past on that specified day, so once the day has passed then he cannot go back to that date to change it, and then he cannot change the previous course of actions this meant he has only one chance to change things every time he goes in the past.