Books like Mystery of the Samurai Sword

I always enjoy a good (old) Hardy Boys book. They're rather predictable, yes, and sometimes a bit far-fetched but still...it's kind of relaxing and it's just good fun to me. This was your typical Hardy Boys book... I liked it. It kept the pace pretty well and I was greatly amused by some of the descriptions of Japanese characters in it. I've lived in Japan all my life so some of it was rather laughable, but still, it was funny, and I did appreciate that throughout the whole book the Japanese people were spoken of respectfully even though it covered some stuff from WWII. I also thought the part about the Yakuza (Japanese Mafia) was neat... I think I might actually know a retired Yakuza haha--and the descriptions in the book was like "Yep, sounds about right!" :P Overall a pretty good read. :)