Nice Day for a Little MermaidChiisana O’Ningyo Biyori, Chiisana Oningyo Biyori, Chiisana Oningyo Hiyori , The Daily LIves of Tiny Mermaids, 小さなお人魚日和, Tiny Mermaid Matters

In the near future, mankind creates mermaids through the selective breeding of small fish. This is the story of three tiny mermaids who are in a Tokyo pet shop waiting for someone to buy them.