That scar was a double-edged sword, a blessing and a curse altogether.
It was a mark left after the bleeding stopped and scabs healed. A reminder of the war and how he had to leave everything behind.
When the Amanto came and trading goods became the least of people's worries, Sakamoto Tatsuma, a self-proclaimed pacifist, joined the war. He told himself it was not because he enjoyed fighting but because he wanted to protect his countrymen. So he became a Jouishishi and fought side-by-side a band of samurai. He supported the group in the front and also sidelines - as a soldier and a merchant. He raised funds for weapons and armory, making sure everything is accounted for.
Hence, Sakata Gintoki, Katsura Kotarou, Takasugi Shinsuke including himself fought together to drive the Amanto away and were later known as the Four Heavenly Kings. Their battles earned them titles: Shiroyasha Sakata Gintoki, the Rampaging Noble Katsura Kotarou, Kiheitai Leader Takasugi Shinsuke and Dragon of Katsurahama Sakamoto Tatsuma. Everything went well for awhile. Together with their own troops, the four rampaged all over, all the while resisting the power of the aliens who wanted to take over.
However, everything had to come to an end. For Sakamoto Tatsuma, it came early in the form of a career-ending injury. It happened when he was protecting a comrade. An unexpected misstep lead to an unsightly gash that sent him away from the frontlines. It was evident the way it looked that recovery would take longer than the normal wound. Healing also does not mean his hand would work good as new. Takasugi and Gintoki promised to take revenge. He laughed it off, but was nonetheless thankful. His friends got his back, he will be alright.
Long after the wound healed and the scar remained, he could still not wield a sword the way he did. During this time though, Tatsuma was tired by the pointless fighting and bloodshed. He would not want to be the cause of another life lost, directly or indirectly. The Joui Wars was long over, his comrades gone. It saddened him to think of the lives that were sacrificed and lost. Last he heard, Yoshida Shoyo's students fought their last battle but were caught. The last generation of the defectors were subsequently let go at the price of their master's head.
He felt the need to apologize to his friends for not being around when they needed him the most. So Tatsuma searched for them but only found one in the form of the former Shiroyasha.
Therefore, he asked Gintoki to join him for his quest of greater things(maybe as a form of repentance), but the man declined. Stating that, "I may not show it all the time, but I like Earth." The silver haired man also said, "Go off to space or anywhere you want to stir things up. Fishing for small fries does not suit you. Get a humongous net, cast it into space, and snag a whole planet."
Those words put the brunette at ease once and for all. Now, he was not afraid to leave, someone will be right behind him, protecting everyone. He would not feel guilty anymore for departing. He will keep moving forward, set his sights on the future and never look back. The curse of the scar reminding him how he could not even assist his compatriots in the last leg of their fight became a gift that catapulted him into space. His past will always be a part of him to learn from, but it will never ever slow him down.
Author's Notes: I'm surprised at myself how I was able to churn out a fic this quick, albeit short haha. Sorry but this was not beta-d and so are my other works.
Will be posting this on AO3 and :)