Definitely Robert -- Inon stuff is cheaper in Asia in general than in the U.S./Europe. Japan even more so. This used to be the case even when I was living there in 2012/2013 and it was 77 JPY to the dollar. (It's now more like 120).
MIC21 is a chain in Japan. They have a number of stores, including in Tokyo and Osaka. I bought my first underwater DSRL rig from the Osaka store and saved quite a bit of cash. Luckily, one of the staff there (Yohai-san) spoke a bit of English, and I was able to explain what I was looking for -- ah, good memories!
If you're traveling through Japan, it's a great place to practice some currency arbitrage and save on camera gear (both in general and for underwater photography stuff). You should always try to negotiate a discount, too, especially if you're buying multiple items. My understanding is that most buyers end up getting a 10-20% discount on the listed prices.
Just watch out -- the mark-up on regular (imported) dive gear at Mic21 (and other Japanese stores) is insane! If you're living in Japan long-term and you need to buy scuba gear, keep in mind that some of the U.S. online stores like ScubaToys and (I believe) LeisurePro will ship there. This can be a great option for avoiding the outrageous markup the local stores charge.