"On & Off" (겉과 속) by Han Seung Woo is a song that explores the concept of hiding one's vulnerabilities and emotions from the outside world. The lyrics suggest that everyone, including the singer, has weaknesses and insecurities that they conceal from others. The constant struggle between portraying a strong exterior and dealing with internal struggles is depicted throughout the song. The song emphasizes the importance of being true to oneself and expressing one's emotions without suppressing them. It encourages listeners to embrace their true selves and not be afraid to show vulnerability. The lyrics also touch upon the idea that life is a constant balance of happiness and sadness, and that it can sometimes feel burdensome to navigate both emotions. The chorus expresses the desire to live authentically and freely, without conforming to societal expectations. The lyrics encourage listeners to live their lives as they wish, without being swayed by the opinions and judgments of others. Overall, "On & Off" conveys a message of self-acceptance and the importance of embracing one's true emotions and identity. It encourages listeners to live their lives authentically and not be afraid to show vulnerability.