These are my own opinions, they aren't based on the characters' actual birthdays. Don't be offended by the character I give you, please!

Aries: Tengen Uzui (Aries are stereotypically highly competitive and prefer to take the initiative)

Taurus: Yushiro (Taurus are stereotypically stubborn and possessive)

Gemini: Kanao Tsuyuri (Geminis are stereotypically kind, yet tense)

Cancer: Tanjiro Kamado (Cancers are stereotypically kind and caring)

Leo: Inosuke Hashibira (Leos are stereotypically a natural leader and impatient)

Virgo: Shinobu Kochou (Virgos are stereotypically faithful and patient)

Libra: Kagaya Ubuyashiki (Libras are stereotypically idealists and diplomatic)

Scorpio: Genya Shinazugawa (Scorpios are stereotypically brave and fierce)

Sagittarius: Obanai Iguro (Sagittarius are stereotypically independent and brutally honest)

Capricorn: Giyu Tomioka (Capricorns are stereotypically persistent and realistic)

Aquarius: Sanemi Shinazugawa (Aquarius are stereotypically assertive and independent)

Pisces: Tamayo (Pisces are stereotypically nurturing and understanding)