Booking through Klook is convenient: I recommend purchasing tickets in advance from Klook. You won't have to wait in line to buy tickets, and the price is slightly cheaper than walking in. The aquarium itself isn't very large, but you can walk around until you reach the dolphin show (you can watch the show without scanning your ticket) and the turtle tanks. It's a decent distance and well worth it. The staff provides excellent service, with both Japanese and international employees available to answer our questions.