Mars shows what a woman is attracted to in a man. Being with a man who is strong in her Mars element, or who makes close sextiles with her Mars, makes the relationship much easier, and increases sexual desire and compatibility. For a man, his Mars is part of his masculine nature, so it is best when his partner also relates well with this element.
Mars Square Pluto
You can struggle with your partner over power, over dominance, over sex, over possessiveness, but you can also use these energies to focus on cooperating and directing them toward a shared objective. Forces outside your union or control will challenge your relationship. The intensity of fury generated between you is Pluto only to the passions you both carry and the power you can raise to overcome obstacles. When the Mars person is square the Pluto person, they will be challenged by the world and by a desire to penetrate to the essence and uncover hidden truth, no matter where that may take him/her.