Katsuki and Eijirou were great at keeping secrets from everyone else. Nobody else knew that Kirishima's hair was dyed every two months or that he was nothing like the manly men he looked up to. Nobody else knew that Bakugou was afraid of failure or that he'd regret everything he'd done in the past. And, of course, Nobody else knew about whatever this was that was going on between them. The rest of what they harbored were secrets, but this... This was an oath (Or: following Katsuki and Eijirou's "complicated" friendship over the story of mha so far!) ORIGINALLY POSTED BY ME TO AO3 (@LOKICHOKI)