My friends and I were talking about characters for a Samurai game we were playing and one of my friends talked about applying the prong to the back of his katana. Now I know that there were many different styles of Tsuba and that it is a possibility. Even my sensei and I discussed how it could have been done, but we were wondering if there is any evidence of a katana (or other sword from Japan, but must be a sword) having a prong like attachment similar to the jitte or sai. (I also know of the anime with the character having something similar, I am concerned with only historical accuracy.)
This is probably a question better suited to r/SWORDS but I'm fairly certain the answer is no. There wasn't a lot of variations in sword design in feudal japan because of a number of reasons, some cultural and some economic. Iron is hard to get in ancient japan because they had to make it from sand rather than mining it. Less iron mean less experimentation. Nobody is going to fiddle around with new designs when they only have just enough iron to fill their quota. That's not to say that experimentation didn't happen its just that it wasn't as widespread as with european craftsmen. Also there wasn't a need for changing sword design because armor designs stayed relatively the same. Also, unlike Europe that had constant war for thousand of years, Japan had several looooong wars that had loooong periods of peace in between. You might have people developing new weapon tech like crazy during a hundred year war but then make all the same old stuff for the next 200 years of peace. Really samurai as we think of them spent more time as bureaucrats than warriors and thus their swords spent more time as a status symbol than as murder tools.
TLDR; The answer is no. There wasn't a widely used katana variant with hooks on it. Its possible that there might be some weird, unique, or rare examples though so I'd double check with r/SWORDS. Those guys are super smart.
Edit: added a word