Wolverine is in Madripoor on Wolverine-in-Japan-related business travel. There's a talisman being couriered to Mariko, and someone had murdered an entire 747 of people to get information about it. Wolverine has revenge to take, and people to protect.
Problem is the courier is Lindsay McCabe, Jessica Drew/Spider-Woman's business partner, who knows him as Wolverine. And he doesn't want to break the "X-Men are dead" line. So he wears and eyepatch and calls himself Patch. What he doesn't do is skip the morning hair routine, but then how else would we know it was him?
Lindsay is just a decoy: Jessica is being sent with the real thing. The Silver Samurai finds out and attacks her, and we find out that the item is the Black Blade, which is like the Black Blade, but more Japanese, which is to say it gives its bearer supernatural powers. Drew uses it to defeat the Samurai, and then we discover it has possessed her and Wolverine has to take her down. Unfortunately, this doesn't work out very well and he merely becomes the latest victim of the weapon.
This is probably not a great thing to happen, especially as its plan is to sacrifice Jessica. So, Lindsay, Samurai and O'Donnell from the MPC story team-up. The end is an anticlimax: the Samurai takes the blade, is not transformed because handwaving, and then Wolverine allows him to walk off with it, apparently content that none of his allies died. The 747 of people is forgotten. It's plain that Samurai recognised Logan for who he was, even if Lindsay and Jessica are none the wiser, so perhaps Logan is doing the discretion rather than valour thing.
The Black Blade is described as a "dai-katana", which is not in fact the name of a type of sword; but that didn't stop John Romero making a game called it, which features a sword with special powers (of time travel, as I understand it). Romero attributes the name to a D&D campaign that he and other people at ID played when they were just starting (in the early 1990s). I'm guessing John Carmack got it from here: he certainly knows his comics. In any case, "katana" (かたな) is just Japanese for any type of sword. Its use in English to mean a Japanese sword is a typical example of semantic narrowing when words are borrowed. Wolverine should know better: but unfortunately Claremont does not.