Does this come with a case of some sort?

Yes, my recollection is that it came in a nice gift style box that displayed the piece well and made a good gift if your intention was to gift it.

Guaranteed the diamonds are real?

It has Eight genuine diamonds accents

Are those real diamond?

I’m not sure, but the stones are very pretty. This question should be addressed to the seller. I purchased this watch for my husband and he loves it!

Does it come with a certification??

If you are asking if the Bulova Men's Diamond watch is certified to be a Bulova, all of the paperwork and packaging, as well as the watch face itself, indicate that it is truly a Bulova. Also, it looks exactly like the last one I had. If you are asking if the Bulova Men's Diamond watch is certified to be for men, I saw no paperwork indicating its gender, and I do not know how to determine either its gender or preference. If you are asking if the diamonds in the Bulova Men;s Diamond watch are certified, you can trust that they are real. Certification of diamonds is a marketing scam. Are the diamonds in a diamond drill bit certified?