[MamoruUsagi]

Fushigi Yuugi
Ayashi no Ceres
Sailor Moon

are great romance/fantasy

Kare First Love
Mars
The Devil Does Exist
High School Debut
Sand Chronicles
Happy Hustle High

are great romance/slice of life manga

Missile Happy!
Wild Act
Ultra Cute
Doubt!!

are good romance/comedy

Fushigi Yugi and Ceres Celestial Legend are great romance/fantasy manga.