I made a Zodiac sign break-down of the franchise, and deduced that the writers hate Sagittarius.

NEOROMANCE ZODIAC SIGN BREAK-DOWN

Aries: 8 main, 3 minor
Taurus: 5 main, 3 minor
Gemini: 9 main, 3 minor
Cancer: 6 main, 3 minor
Leo: 9 main, 2 minor
Virgo: 7 main, 3 minor
Libra: 8 main, 3 minor
Scorpio: 7 main, 5 minor
Sagittarius: 5 main, 1 minor
Capricorn: 9 main, 2 minor
Aquarius: 5 main, 2 minor
Pisces: 8 main, 1 minor

MOST MAIN CHARACTERS
9: Gemini, Leo, Capricorn
8: Aries, Libra, Pisces
7: Virgo, Scorpio
6: Cancer
5: Taurus, Sagittarius, Aquarius

MOST MINOR CHARACTERS
5: Scorpio
3: Aries, Taurus, Gemini, Cancer, Virgo, Libra
2: Leo, Capricorn, Aquarius
1: Sagittarius, Pisces

LEAST TO MOST LIKED SIGNS (main and minor)
6: Sagittarius
7: Aquarius
8: Taurus
9: Cancer, Pisces
10: Virgo
11: Aries, Leo, Libra, Capricorn
12: Gemini, Scorpio

AIR SIGN (Gemini, Libra, Aquarius)
Main: 22
Minor: 8
All: 30

WATER SIGN (Cancer, Scorpio, Pisces)
Main: 21
Minor: 9
All: 30

EARTH SIGN (Taurus, Virgo, Capricorn)
Main: 21
Minor: 8
All: 29

FIRE SIGN (Aries, Leo, Sagittarius)
Main: 22
Minor: 6
All: 28