"Kokoro ga Uruou Kirei Aquarium DS" as the name suggests, allows you to manage your own aquarium.

Two versions will be available on March 29th featuring different creatures. One offer you tetras, guppies and angel fishes while another will give you whales, dolphins and penguins.

Think I would prefer the version with penguins and dolphins!

Source:
• Famitsu

Related Links:
• Ertain Company Press Release (PDF)