They appear very similar to each other because the S (Sensing) types, N (Intuitive) types, and F (Feeling) types, T (Thinking) types partially align, creating an optical illusion of similarity. However, they are fundamentally different, and since they don't share a single matching psychological function, their psychological function directions are opposite, which is why it’s called a Contrary relationship. Unfortunately, they are opposites in almost every aspect. Therefore, they face many conflicts and communication barriers. For example, when one person is an Extraverted Feeling (Fe) type and the other is an Introverted Feeling (Fi) type, the Extraverted Feeling (Fe) type person focuses on the outside world and thinks from the perspective of others. However, the Introverted Feeling (Fi) type person focuses internally and makes judgments based on their own internal standards. So, they fail to understand each other. In a Contrary relationship, since they don’t possess each other’s inferior or tertiary functions as strengths, they can’t perfectly complement one another. It’s an incomplete complementary relationship. Therefore, the idea that many people call ideal is actually wrong. They have a lot of potential but also many difficulties.