Sparkling Watermelon episode 12 starts with Eun-gyeol reaching the school premises on time to help Yi-chan. The cops arrive as well and the goons run away from the area. However, Yi-chan remained confused about the incident as he remembered when Eun-gyeol told him he was Yi-chan’s father and that he had come for the future. However, Eun-gyeol is able to deflect the situation by saying that he lied earlier and only wanted to keep Yi-chan safe so that he could perform at the festival.
On the other hand, Eun-yoo gets upset with Eun-gyeol for leaving her stranded on the date and she feels like she was abandoned again. Eun-gyeol tries hard to apologise and make the situation better but she avoids him constantly. When Cheong-ah asks her who she will choose between Eun-gyeol and Yi-chan, she reveals that she will choose Yi-chan which leaves Cheong-ah upset.
The band gets ready for the performance and arrives at school to invite the students. Yi-chan meets Cheong-ah and invites her to the festival as well. She hands him a gift, which is a guitar pick and Viva la Vida is written on it. When Eun-gyeol reaches home he is called by the chairman for a word. The chairman says that he will extend the contract period for one month and asks Eun-gyeol to make Cheong-ah smile at him so their relationship becomes better.
The day of the festival finally arrives and the band starts to play their songs. In the audience, Eun-yoo cheers for them but Cheong-ah does not attend it. However, her friend brings up her father and Se-kyung’s husband and says that he is in a band. Then Eun-yoo realises that her mother’s first love was her father all along and she leaves the festival instantly.
Yi-chan gets upset when he does not meet Se-kyung at the festival and assumes that she rejected her. But as soon as he reaches home he faxes Cheong-ah and urges her to meet him outside her house. He asks her why she did not attend the festival but she gets angry at him and asks to never contact her again. On the other hand, Eun-gyeol waits for Eun-yoo outside her house but she also asks him to forget about her because she belongs to another world.
When Eun-gyeol reaches the house he overhears the chairman’s daughter saying that Se-kyung is about to leave the country. He rushes to the airport but does not find her anywhere. Eun-yoo rushes inside the airport and goes through the same way she arrived in the past and realises that she cannot leave. Eun-gyeol notices her outside the airport helplessly crying and assures her that he will help her out in getting back home.
The new episode remains as exciting as ever. It was a set-up for the final reveal near the end of the episode which played out tremendously well. Moreover, the show has finally moved on from the extended sub-plot and arrived at the core story which will involve the main couples, finding their way back to each other. The episode ends on an exciting cliffhanger which keeps the audience wondering about how the plot will develop moving forward.