First stop is the hotel's onsen, or bathhouse. The hotel is in an area called Wakura Onsen, which is famous for its hot springs. The region was discovered 1200 years ago when legend claims a white heron was seen bathing in seawater to heal an injury. Since then, the Japanese have been coming here to treat all manner of ailments. The waters are supposed to be particularly good for rheumatism, gout and digestive disorders.
Kagaya's two gender-segregated bathhouses are huge, three-level affairs with several indoor and outdoor pools as well as a sauna and jacuzzi each. There is a strict etiquette when visiting a Japanese bathhouse and despite some explanatory English signage in the changing rooms, I'm still a little bemused.
After undressing and putting my clothes in a locker, I wander aimlessly, fuelled by a long-held view that approaching another naked man and asking him to lead me to the showers could be taken the wrong way. Eventually, I stumble across them by accident and, after a thorough scrub, I'm ready to hit the baths.
I lie back in a blissfully hot outdoor pool and watch the sun drain from the sky over the bay, I can finally see what all the fuss is about.
If you were staying at Kagaya on your own, dinner would be served in your room but because I'm here with a group, we dine in one of the hotel's 42 private banquet rooms. Seven low tables, are laden with an intriguing assortment of appetisers, including dried sea cucumber, sea urchin and pickled sea snail. A metal dish over a burner contains abalone that's so fresh it's still moving.
For the next two hours we're presented with a steady stream of delicacies by yukata-clad staff who shuffle reverentially into the room on their knees.
A variety of entertainment options are available after dinner and they're all equally bizarre. The headline act in the Matsuri Festival Theatre is a mime artist; there's a high-kicking cabaret act in the Hanafubuki Club and a forlorn-looking nightclub with mirrored walls and a spinning disco ball stands empty.
Which is why I gravitate to the bar. It's quiet and looks like it could be a temporary sanctuary from all this wackiness. Then the shimmering green Mexicans turn up.
Kagaya has been voted the number one ryokan in Japan for the past 28 years. Which is bewildering given it's about as far removed from a traditional Japanese ryokan as you can get. But I guess that's its appeal. It's like Vegas does Japan - crazy but compelling.