Endless Summer 

After being joyfully reunited with Jin-Han Ryu, the best friend of her brother, Ha-Yeon Ji’s day immediately takes a turn for the worse as the two witness her boyfriend with another woman, right in front of them. After a series of awkward, coincidental encounters between the two, Ha-Yeon and Jin-Han begin to get reacquainted with one another. But after spending some time together, Jin-Han seems to begin seeing her as more than his friend’s little sister. (Source: WEBTOON) Note: Includes three extra chapters.