Welcome to PF.
I can't comment on the particular deal but I would make a few observations:
1. Let's assume the deal includes a Ricoh-Pentax warranty. It is unlikely to cover service outside Japan. You would still have to send it back to Ricoh Japan for service/repair/replacement if you have a problem. That could more than eat up any savings on the purchase price. I bought one camera that didn't have a local (Australian) warranty. Fortunately I didn't have a problem with it, but I would never do it again.
2. The two kit lenses are OK, but won't give you full value from using a DSLR. The K-70 is often sold packaged with a Pentax DA 18-135mm f3.5-5.6. That is a much better starter kit. It is also more convenient for travel as it involves fewer lens changes. The K-70 is also sometimes bundled with a Pentax DA 35mm f2.4 or DA 50mm f1.8, whose excellent image quality belies their low cost and plastic construction. If you want a telephoto lens as well, I would suggest a Pentax DA 55-300mm f4.5-6.3 PLM (not the DA 50-200). This is a really good lens. It is also sometimes bundled with the K-70. You can read user reviews and PF staff reviews of all these lenses by following the links here:
Pentax Lenses - Pentax Lens Reviews & Lens Database Buying a new lens in a bundle with the camera is usually a lot cheaper.
3. Although you are familiar with a film SLR, there is a bit of a learning curve with a DSLR. If your trip to Japan is a vacation, I'd suggest buying the camera and getting familiar with it before you go. Trying to learn to use the camera after you arrive in Japan is not a recipe for a happy holiday or satisfying photography.
4. Whether you buy before you go or not, start reading up now.
- There is a lot of helpful information in the PF review of the K-70:
Pentax K-70 Review - Introduction | PentaxForums.com Reviews
- The manual and starter guide can be downloaded from Ricoh:
Operation Manuals Download : Support & Service | RICOH IMAGING
- I'd strongly suggest getting the excellent ebook written by the late lamented PF member Yvon Bourque:
https://www.pentaxforums.com/forums/donations/?ebooks=1&loginrequired=1#sub42
- There is a wealth of other useful information on the PF site.
5. For second-hand K-mount lenses, Japan is regarded as a treasure-trove. Dealers generally have a good reputation. Other members can suggest places to go if you are interested.