Thumpalumpacus
Major
If you read Destroyer Captain by Captain Hara then yes the IJN did have ASW capability and did attack and sink submarines.
I've read that. Perhaps you can quote the passages wherein he describes the missions he spent on ASW?
Whether it was good or bad is neither here nor there. That's a IJN problem and not a me problem.
None of this is a "me" problem. But the short-shrift the IJN gave to ASW was certainly a "them" problem. It affected supply into home-island factories. Hell, IJN kept a good proportion of its fleet south not because it was strategically sound, but because it kept major fleet units closer to their fuel sources. That's quite the admission that getting the oil back to Japan was more difficult than expected, don't you agree?
The Regia Marina was still sailing convoys to North Africa into the early months of 1943. So again...yes with heavy losses but it was still functional. Good or bad is again a RM problem.
I'm struggling to think of one RM intervention that made any sort of difference after Pedestal. Can you help a brotha out, perhaps by citing a source?