Eastern compatibility (宮合, gunghap) has, broadly, two layers of view. One is “surface compatibility” (gyeot-gunghap), the other “inner compatibility” (sok-gunghap). Surface compatibility mainly compares the zodiac animals of the birth years (the twelve branches): whether the two animals suit each other well, how first impressions and social temperaments meet — the harmony of the grain shown outwardly, so to speak. It speaks of well-matched combinations like the three harmonies and six unions, and clash-prone ones like the clashes and penalties.
Inner compatibility steps one further in. Rather than the single animal, it compares the two people’s whole saju — the energies of the year, month, day, and hour of birth — to see how temperament, values, and the rhythm of life harmonize at a deep place. So there are pairs who seem plain on the surface yet fit well within, and conversely pairs dazzling at first whose grain runs crosswise for the long haul. The old saying “inner over surface” meant that a lasting bond comes from the harmony of the deep grain.
But here is something to remember well. That one side of the compatibility comes out poorly is by no means a verdict that “this love cannot be.” Compatibility is only a mirror reflecting where two people are alike and where they differ. Indeed, knowing in advance the “places prone to clash” lets you show a little more care and talk it through there — so “the compatibility doesn’t match” can also mean “a map for where to make effort has appeared.”
So there is no need to be frightened or discouraged, rising and falling with a compatibility result. No compatibility in the world can stand in for two people’s devotion and conversation. Cherish a compatibility that fits well, and take the places that run crosswise as clues for understanding each other. As FortuneLeaf always does, what surface and inner compatibility offer is not a report card grading a bond pass or fail, but a soft reflection that lets you tenderly understand two people’s differences — for the best compatibility is not something you are born with, but something built together through the heart you turn toward each other.