Kokoro ga Uruou: Birei Aquarium DS - Kujira, Iruka, Penguin features 5 different sized tanks to choose from, which can be customized with different backgrounds, plants and accessories such as rocks and bridges. Then choose from more than 30 aquatic creatures that could never be kept as pets such as blue whales, dolphins, seals and killer whales. Learn to create the optimum environment for your aquatic friends controlling everything from water temperature to the salinity of the tank, while keeping it clean and raising all the pets you want.