Now that we have officially been given the birthdays, zodiac signs (there has been an edit for Vincent, his zodiac sign in the guidebook is Virgo, but he is a cusp with Libra), and blood types, I figured I would do love compatibility based off of the blood types like I did with the zodiac signs.
A: Break, Oswald, Elliot, Yura
Type A are most romantically compatible with other Type A’s or Type B’s.
Some Compatible Pairings: Break/Sharon, Break/Gil, Break/Elliot, Oswald/Gil, Elliot/Sharon, Vincent/Elliot, and so on
(no Yura is not getting any pairings!)
B: Cheryl, Gilbert, Rufus, Sharon, Vincent
Type B are most romantically compatible with other Type B’s or Type AB’s.
Some Compatible Pairings: Rufus/Cheryl, Vincent/Gil, Sharon/Leo, Vincent/Echo, Vincent/Leo
AB: Leo, Echo
Type AB are romantically compatible with all other blood types.
Some Compatible Pairings: Elliot/Leo, Oz/Echo, Alice/Echo, Leo/Oz, Leo/Ada, Vincent/Echo, and the list could go on…
O: Ada, Alice, Lacie, Jack, Oscar, Oz, Reim
Type O are most romantically compatible with other Type O’s or Type B’s.
Some Compatible Pairings: Jack/Lacie, Oz/Alice, Oz/Gil, Oz/Sharon, Ada/Vincent, Oz/Ada, and Alice/Gil
So, it seems to me that Mochizuki-sensei based their personalities off of their Zodiac Signs, while Blood Types were used for romantic compatibility (since we have seen nearly all of these “compatible pairings” getting ship-teased at least once throughout the series).