There are unique, characteristic zoos and aquariums all around the world, then, if you love animals or birds and fish, penguins, why don’t you visit zoo and aquarium while staying at Tokyo.
https://www.tokyo-zoo.net/english/kasai/index.html
Okapi “A lady of the forest” 
Baby Panda sleeping 
Winking white owl 
Daddy panda 
Alpaca like a rock star. 
Polar bear
Tokyo Ueno Zoo (Tokyo Zoological Gardens)and Kasai Rinkai Aquarium(Tokyo Sea Life Park) are being managed their administrations by Tokyo Metropolitan Government.
You can see the animals along scenery close to its natural environment.
Meanwhile, Sumida Aquarium, Shinagawa Aquarium are private aquariums, inclined to be particular about presentation.
https://www.sumida-aquarium.com/en/index.html
https://sunshinecity.jp/en/aquarium/
Animals are endearing, wild, brave, humorous, huge and tiny.
You must see fish and penguins, fur seals, Chinese eels, a school of tunas, jelly fish in Tokyo.
Let’s chill out and watch some wildlife at the center of Metropolis.