@Seojoon you are confusing the information they were saved by daehwi when they fell in the ocean, then jooha lost his memories, in 90 we can see him get discharged and go home with dooshik but not remembering him, after that he fell in the frozen lake trying to save the black cat, the last panel of 90 is them INSIDE THE LAKE no one saved them, 92 is clearly a flashback too you can see the black background and the events, they had already happened
I love you, shizun.
