The ying and yang Chinese theory is that light and dark energy compliment each other. The YIN(dark side) is represented as the female and the YANG (light side) as the male.
Translated to MLB,  Ladybug is yin and Cat Noir is the yang, because that's how their miraculeses are placed in master fu's box(if you remember origins part 1)

It doesn't matter if your sign is yin and you're a boy, yang and you're a girl..what mostly defines if you're yin or yang is your personality, traits and likes..so don't worry!

Aries: YANG ( Cat Noir)
Taurus:YANG ( Cat Noir)
Gemini:YIN ( Ladybug)
Cancer:YIN( Ladybug)
Leo:YANG ( Cat Noir)
Virgo:YIN( Ladybug)
Libra:YIN( Ladybug)
Sagittarius:YIN( Ladybug)
Capricorn:YANG ( Cat Noir)
Aquarius:YIN( Ladybug)
Pisces:YANG ( Cat Noir)