Back then, back during the war, Katsura had stayed on even after Sakamoto and Gintoki had left not out of loyalty to the cause, or even out of some sense of friendship or camaraderie. He stayed through the mock trials and certain executions, the increasingly ridiculous cut downs and exceedingly reckless strategies on the battlefield because he had been there to witness just how badly being abandoned twice over affected Takasugi. He was around to witness every shouting match, every terse conversation leading down to the final break off. He was there, in the other room/just beyond the shoji door, listening in on his comrade as he lost himself to confusion, despair, and – much, much later – rage.
His back soon became the only one Takasugi’s leaned against on the field; his hands, the only pair allowed to touch the leader of the Kihetai whenever the latter’s injuries needed tending to. He refined the battle plans, revised the reports, arranged the rituals, oversaw the assisted suicides. He poured the sake, changed the bandages, prepared the meals, made the bed. He sat through the mad rants and half-delirious rambling, the drunken slurs and broken monologues. And sometimes, when it became clear that Takasugi was going to snap under the pressure, he offered his arms to hide in and his body to fuck.
It wasn’t too long, though, before all of that just wasn’t enough.
When he finally made the decision to break away, Katsura told himself that he was doing the right thing. Their teacher had given them a cause to fight for, a reason to wield their swords; what Takasugi was setting out to do would lead to nothing but madness. It would take him years to realize that what he had been doing was running away, and it was the guilt he felt over being the third and last one to abandon Takasugi that brought him back to the man later, with the beginnings of a plan to rebuild their forces and overthrow the government.
Their relationship is an exercise in falling apart, even after being pinned together by mutual loss, deep-seated bitterness and the overpowering need to be with someone who understands. He knows that every meeting they have is another step in drifting further away from each other. He knows that despite their intimacy Takasugi’s slipping and he doesn’t have the strength to try to fight it off for him. He has left once, though, and until it’s his neck that Takasugi’s holding a sword to, he isn’t going to step away again.