Sunshine City Aquarium, Ikebukuro

Tickets cost 2,400 JPY per adult and 1,200 JPY for children 3-15. Highlights include fur seals performing aerial acrobatics under the open sky and a mesmerizing jellyfish gallery. TripAdvisor rates the Sea Lions in the Sky arena highly for families with kids aged 4-10. Located on the 10th floor of the World Import Mart, it pairs with Namjatown amusement park (400 JPY plus rides), offering a more economical option than a full day at Sanrio Puroland, with 30% shorter travel from central Tokyo.