Mariko first appears in X-Men #118. By the time you get to the 1982 Wolverine miniseries, Logan has a very personal reason to be in Japan, and things have gone badly wrong for her.

Mariko first appears in X-Men #118. By the time you get to the 1982 Wolverine miniseries, Logan has a very personal reason to be in Japan, and things have gone badly wrong for her. Her father, Shingen, has married her off. Logan wants to help, but Shingen knows how to use the situation against him. Logan is poisoned before their confrontation, then beaten and humiliated in front of the woman he loves. So the guy who is normally so eager to get into a fight has walked into one where the other man has already arranged several advantages. Being angry doesn't help him see through all of that. Yukio is involved too, and she brings another set of problems. Logan has to work his way through the people around him instead of assuming he can solve everything by getting his hands on Shingen. Then the X-Men come to Japan in Uncanny #172–173. Rogue gets badly hurt protecting Mariko, and Logan lets her take his healing power even though he needs it himself. Considering how much reason he has to distrust Rogue, that is a big thing for him to do. She risks herself for Mariko, and he responds to that.