I wouldn’t be surprised if Jack is dead at the end (and Ashi takes his place or something), but yeah I think they’ve probably done their service to the harakiri/seppuku possibility. Which is pretty cool honestly because it’s such a big part of samurai culture but was obviously never even something that would have been so much as mentioned on the show when it was more kid-aimed.
Not to mention evil spirits trying to drive the hero into committing it.