Sun opposite Mars (orb 0.5°) puts the two planets face to face, with visible back-and-forth or tension. The orb is extremely tight; this aspect is one of the chart's strongest signals.
Here, Sun in Sagittarius in House 7 brings identity, ego, father figure, visibility, and direction into House 7 (relationship, confrontation, and the mirror of others), with Sagittarius style (expansion, travel, belief, and the search for meaning); Mars in Gemini in House 12 brings action, courage, competition, and effort into House 12 (retreat, contemplation, long time, and possible confinement), with Gemini style (curiosity, language, movement, and mental adaptation).
Concrete conflict: this aspect sets ego or father image against Mars: direct action, anger, or competition can conflict with confidence, sometimes through a weak, absent, inhibiting, or castrating father image. Visible angle: Sun near the Descendant (orb 0.4°) and Mars near the Rising sign (orb 0.1°) touch angles; this aspect is easier to notice through direct relationships, partners, opponents, and the way others are met; also through first impression, body language, reflexes, and entry style. The house conflict is between House 7 (relationship, confrontation, and the mirror of others) and House 12 (retreat, contemplation, long time, and possible confinement); pressure in one field tends to reactivate the other.