the watches are a high end fast fashion brand in japan. it seems to be very lucrative
Not just Japan, they're widely popular globally as daily drivers, but also as "fashion" watches, with Gen Z too.
80s casio watches are the rage with kids in the US, too
I have a couple of Oceanus brand watches that I got in Japan. They are fairly un-cheap.
However, in Japan, their G-Shock brand (kind of lower cost, in the US), can get even more expensive than Oceanus. Some of them look like Pip-Boys (Because this is HN, I need to mention that this is a deliberate exaggeration).