Not yet. I did listen to the theme song in French and understood. "I am a cat."
I did find myself singing a little Japenese the other day since the Sailor Moon DVDs I watch have the theme song in Japense even in the dubbed versions.
Gomen ne sunao ja nakute...yume no naka nara ieru...For some reason the Japanese theme of Sailor Moon gets played a lot at Japanese kind of events in the UK. Maybe that's why...I don't think I've ever heard it in English. I have genuinely ended up with that stuck in my head for weeks.
Weird fact - when I started learning Japanese, one of the things I did was find the lyrics for some of the theme songs I liked and I learned the entire lyric without understanding a word. I can still sing these songs but now I realise what I'm singing about xD. Most especially the theme to Yami no Matsuei, Eden, which is lovely, dark and creepy.
But actually doing that helped me to learn certain grammar structures as I went forwards. I also actually tried to translate (with a lot of success) Japanese song lyrics really early in learning Japanese, and so that also helped me to get to grips with the grammar sections. But I kind of don't recommend my way of learning language to anyone, it's insane...I was literally translating and writing out every single word and phrase from a Fushigi Yuugi novel I had in Japanese in order to understand it. It actually came out better than I expected given that I'd done 6 months of Japanese at the time, but it isn't the most sensible way of obtaining vocab and grammar unless you want a basis of wordage about demons, monsters, spells and curses...and a bunch of kanji you will probably never see again!
However I do think exposure to the language you want to learn, even at a high fluent level (like watching TV) is a good way to acclimatise the ear and the brain to the language. Just maybe not at my weird extreme. Listening to songs in a language is supposed to make it easier to learn the grammar than if you just heard it spoken. So I've been told anyway. It certainly seemed that way to me...although you have to beware of colloquialisms.
Also yes! Chat Noir does say he's a cat in the theme, doesn't he xD.