Seungjoon Lee (Korean: 이승준, Lee Seung-joon) is a supporting character in Season 1. He was first introduced during Seonji's flashback story and returns when Nari is attending summer academy, eventually befriending her and reconnecting with Seonji. He attends Hyowon High.
Background[]
When Seungjoon was in middle school, he met and developed an immense crush on Seonji, and asked her out multiple times despite her refusal. When he found out that Yeseul was friends with Seonji, he faked interest in Yeseul to get close with Seonji. Yeseul is hurt when she realized his true intentions, and she decided to leverage the situation in a way to get revenge on Seungjoon, as well as gain the upper hand over Seonji.
Yeseul told Seungjoon that she was aware of his feelings for Seonji, and proposed to help him with Seonji. He was duped by Yeseul into pretending he was Yeseul's boyfriend. Yeseul went on many fake "dates" with Seungjoon, in an effort to make Seonji jealous. She then told Seungjoon to confess to Seonji, knowing that Seonji was not interested in Seungjoon at all.
Seonji was upset when he confesses to her, as she thought he was going out with Yeseul now. She criticized him for pushing his unwanted affections on her, and blamed him for only thinking about himself rather than her situation. Seungjoon is crushed when he hears this, and finally realized that Yeseul played him all along. He called Yeseul after this realization to confront her. He admitted to Yeseul that although she lied to him on purpose, he was also in the wrong for involving her in the first place, and decided to just call it even between then.
Unbeknownst to Seungjoon, however, Yeseul also used the situation to make it seem as though Seonji stole her boyfriend, despite the fact that Seungjoon wasn't truly her boyfriend in the first place. When he found out about this, he stormed over to Yeseul and Seonji's class to set the record straight, but was stopped by Seonji, who didn't want Yeseul to suffer because of her. As a result of this, Seonji was seen as guilty by all the girls in her class, and became an outcast for the remainder of her middle school years.
Seonji and Seunghoon crossing paths in Season 1, Episode 132.
Seungjoon later meets Seonji again during high school, when she was working at the Turtle Bakery. Seonji forgave him for everything that happened earlier, and they were able to make a fresh start.