Lee Kyung-do (played by Park Seo-joon) revealed his feelings to Seo Ji-woo (played by Won Ji-an). In the fourth episode of JTBC drama "Waiting for Kyung-do," which aired on the 14th, Lee Kyung-do was shown worrying about the ill Seo Ji-woo. He carried the unconscious Seo Ji-woo on his back and headed to the hospital. Afterwards, he carefully took care of Seo Ji-woo's daily life, acting as her guardian.

Upon learning that Seo Ji-woo had taken alcohol and medication together, Lee Kyung-do asked, "Why did you take the medicine?" Seo Ji-woo explained, "My mom came, so I did. I wasn't trying to die," referring to her taking sleeping pills. Lee Kyung-do visited Seo Ji-woo's house, threw away all the alcohol, and expressed his concern. His feelings did not change. He continuously showed worry by sending Seo Ji-woo videos related to alcohol addiction. Lee Kyung-do said, "I'll come to see you often," calling himself a "custodial guardian" as he stayed by Seo Ji-woo's side.

Seo Ji-woo and Lee Kyung-do grew closer as they walked barefoot together. However, Seo Ji-woo's ex-husband Jo Jin-eon (played by Oh Dong-min) showed up at her house without warning. At that moment, Lee Kyung-do appeared pulling a suitcase and witnessed the situation. In response to Jo Jin-eon's provocation, Lee Kyung-do declared, "I'm flirting. I'm doing my best," clearly expressing his feelings. This statement created tension for the upcoming developments.

Lee Kyung-do continuously showed concern for Seo Ji-woo's health. To prevent her from drinking, he began persuading her, saying, "Don't drink." He criticized Seo Ji-woo's behavior, saying, "Why would you go if you didn't drink? You wouldn't have gone if you hadn't drunk." Seo Ji-woo sometimes got annoyed by Lee Kyung-do's worries, but he replied, "It's humanity," conveying his sincerity.

In the spring of 2007, Lee Kyung-do gave Seo Ji-woo a dress he bought with his part-time job earnings. Seo Ji-woo also wanted to buy clothes for Lee Kyung-do, but when she saw him paying in full for a dress costing over 300,000 won, she realized their reality. Lee Kyung-do's mother earned 300,000 won a month from a side job. Seo Ji-woo sensed that Lee Kyung-do had changed.

When Lee Kyung-do suggested going to eat pork cutlet instead of tteokbokki, Seo Ji-woo felt upset and said, "Because I'm the daughter of Jarim Apparel, is it uncomfortable to suddenly eat street food?" Lee Kyung-do retorted, "Don't you think about my position? Everyone around me is like me. It would be nice if you gave me time to adjust," and said he even borrowed money to buy the pork cutlet. Lee Kyung-do tearfully confessed, "I know this isn't right, but my parents working hard was very natural. But after meeting you, things that were natural started to look different."

Seo Ji-woo eventually apologized, and later, after falling ill, she was taken to the hospital. Seo Ji-woo was about to leave for New York. Currently, Lee Kyung-do has been continuously sending Seo Ji-woo videos about alcohol addiction, and Seo Ji-woo visited Lee Kyung-do at work to express her dissatisfaction. Lee Kyung-do was preparing for an overseas training program in Chicago, but his concern for Seo Ji-woo came first. Even while eating meat with friends, he took care of Seo Ji-woo by bringing her meat and grilling it for her, calling himself a "custodial guardian."

However, Seo Ji-woo called Lee Kyung-do out to Juwon and declared that she was really going to leave. She said she would find meaning in Lee Kyung-do's words and told him, "If you catch me again, then you'll be confused too." That night, Seo Ji-woo's ex-husband Jo Jin-eon punched in the password and barged into her house. While Jo Jin-eon was threatening Seo Ji-woo to start over, Lee Kyung-do appeared pulling his suitcase. Lee Kyung-do sarcastically asked Jo Jin-eon, "What's going on?" and declared, "I'm flirting. I'm doing my best."