Ou Dorobou Jing

Synopsis

The first episode takes place in a town called the Capital of Thieves, as Jing and Kir attempt to steal the mysterious Double Mermaid jewels, which in actuality are living beings. The Double Mermaid is kept at the top of a large tower that the tyrant in charge of the town has constructed. Many thieves have died trying to get to the top of this tower. Eventually Jing is able to make a giant bird angry enough to grow wings and fly him to the top of the tower. The item that Jing steals is the jewel that was created by the mother's and daughter's tears mingled together.

(Source: Wikipedia)