Osaka Aquarium Pass
Osaka Aquarium Kaiyukan is said to be one of the best aquariums in Japan. If you want to pay it a visit, I highly recommend “Osaka Kaiyu Ticket”. The pass includes the entrance fee of 2,500 yen, some discounts for touristic spots, shops, restaurants, etc., and transportation – one day unlimited rides of Osaka subway (2,550 yen) and optionally return ticket of some of the following privet lines: Hanshin (2,960 yen), Kintetsu (3,170 or 3,580 yen, depending on the area), Nankai (3,010 yen), Kitaosakakyuko (2,660 yen), Hankyu (2,960 yen), Keihan (3,100 yen), Semboku (3,120 yen), Shintetsu (3,580 yen) and Nose (3,270 yen). The price depends on which line you use (it's a return ticket), but always includes unlimited rides of the Subway and the aquarium entrance fee. The pass for children bellow 16 years old is about a half. You can buy it generally at any station of the lines written above.
For more detailed information visit: www.kaiyukan.com/info/admition/kaiyu_ticket/