She just wants to start fresh so she can graduate in peace. She just wants to leave behind all the bad memories — her sleepwalking, the trauma from being bullied at school — all of it. She did everything she could to keep to herself, but the class president, Hae-On, just won't leave her alone. One day, when Seul-Bi visits the local lake Hae-On recommended, she comes across something she never imagined seeing in her wildest dreams: a wild, dark mermaid. (Source: WEBTOON, edited) Note: Includes one extra.