Square · 90° apart
Square
Same modality, clashing elements. Genuine friction, and genuine momentum: this pairing produces change, not comfort.
Fire · Mutable · ruled by Jupiter
Brings. Genuinely open-minded and hard to discourage. Says the thing nobody else will.
Struggles with. Says it without checking whether it needed saying, and leaves before the consequences land.
In love. Needs room and honesty. Reads possessiveness as a threat rather than devotion.
Water · Mutable · ruled by Neptune (traditionally Jupiter)
Brings. Feels what other people feel, often before they do. Creative without forcing it.
Struggles with. Absorbs moods indiscriminately and retreats into fantasy when reality gets loud.
In love. Devoted and idealising. Prone to loving a version of someone rather than the person.
Sagittarius is mutable fire; Pisces is mutable water. Sharing a modality means handling change the same way, which sounds helpful and often means competing for the same role.
Sun signs are one factor among many, and astrology itself treats them as a starting point rather than a verdict. Two full charts describe far more than two birthdays do.