Although D2 isn't quite stainless by the strict definition, it's pretty close to being so, just a bit shy of the 11-12% free chromium content needed to be called 'stainless'. Some of it's chromium goes to forming very wear-resistant carbides, instead of to corrosion resistance. But it's still not easily prone to rusting like other carbon steels (1095, etc.).
Just treat it like you would a stainless blade. Keeping it relatively clean after use will accomplish about 99% of the task. Oil it if you want to - but you might eventually find you don't really need to do that. You might notice over time, it might begin to patina just a little bit, with some subtle graying of the finish. But there's no harm in that and no need to worry.