Took the OW course. Wasn't sure I would even enjoy diving but gave it a go. Have to say it was not something that came easily to me, starting from nothing such as how to put on a wetsuit.
Despite attentive and persistent advice from instructor Frank I was having some mental issue with my breathing, overly-fast, deep breaths, no buoyancy control, physically tired. My own subconscious 'technique' to avoid dying underwater.
Frank convinced me not to drop out, though by that point it would have saved the school time, money and hassle to let me go with the lesser available certification. Things turned around on my 4th sea dive with mostly 1 on 1 training and I later finished the course with another complimentary dive much happier and confident that I could dive safely and effectively.
Can't compare this to anywhere else, but the equipment liked fairly new, staff were all friendly and helpful.

Good location. No time wasted getting from the school to the open water training 'wall' dive site (2 minutes in boat from the beach) , which gives the training dives the environment / atmosphere of a 'real' dive.
Highly recommended.

I did my AOW course in this shop 3 years ago, and did 3 fun dives a few days ago. Everything is really well organized, their gear and boat are somewhat brand new, staffs are kind and try to help everything.

Especially their full time manager(she is also instructur) can speak both Japanese and English, so it would be a good choice if you feel comfortable for Japanese communication.

Their price is not really beneficial when you do not bring your own gear. However, it is located just next to the Lost Horizon Resort; so if you stay at the Lost Horizon (and have enough budget), it is still good choice.