[MamoruUsagi]

Bokura ga Ita
Fushigi Yuugi
Paradise Kiss
Ayashi no Ceres
High School Debut
Mars
Kare First Love
The Devil Does Exist
Peach Girl
Kare Kano
Marmalade Boy
Ultra Cute
Sailor Moon
Wild Act
Happy Hustle High
Akuma De Sourou
Absolute Boyfriend
Sand Chronicles
Fushigi Yugi
Missile Happy!
B.O.D.Y
Ceres Celestial Legend

Mars is a great mature romance manga, the couple is boyfriend and girlfriend and dating and in a mature, deep, committed relationship. Rape, engagements, suicide, secret pasts, living together and many more deep secrets. A deep, realistic, mature romance. Most mature romance manga.

These are great manga and anime that show the couple as boyfriend/girlfriend, dating and in committed relationships.

I'll add more descriptions soon.

Bokura ga Ita
Fushigi Yuugi
Ayashi no Ceres
Mars
The Devil Does Exist
Kare Kano
High School Debut
Peach Girl
Sailor Moon
Paradise Kiss
Kare First Love
Wild Act
Happy Hustle High
Absolute Boyfriend
Akuma De Sourou
Fushigi Yugi
Ultra Cute
Sand Chronicles
Ultra Maniac
Ceres Celestial Legend
Marmalade Boy
Missile Happy!
B.O.D.Y