I want to know the name of an anime that was very popular in the eighties.?!

It's the story of a girl whose cat swallowed a necklace or some very expensive jewel!. So the princess (owner of the jewel) and a thief chase her in order to get the cat and recover the jewel!. Both the princess and the girl fall in love with the thief!. The thief falls in love with the girl!. In the end, it turns out that the girl and the princess are half sisters!. The cat had surgery and they took out the jewel!. The girl and the thief live happily ever after!.
I think that the name of the thief is Phoenix!. That's the only name i can remember!. Thanks for your help!Www@Enter-QA@Com

---

---