The Chinese idiom "一见如故" is formed by combining four characters: 一 (meaning "one" or "once"), 见 (meaning "see" or "meet"), 如 (meaning "like" or "as"), and 故 (meaning "old friend"). The sequence structures a literal meaning of "upon first meeting, like an old friend", where 一见 denotes the initial encounter and 如故 establishes a comparison to the familiarity of a long-known acquaintance, thereby directly conveying the concept of immediate affinity.