Twinkling Watermelon

Eun-gyeol, a CODA and the only hearing person in his family, often feels isolated, feeling like living in a different world. After being bullied, he is drawn to music and meets a music store owner. He begins learning guitar, finds his talent and joy in music. Meanwhile, Yi-chan falls in love at first sight with Seowon Art High’s goddess, Choi Se-kyung, whom he knows only through rumors.

While secretly busking, Eun-gyeol is scouted by Spine9 and offered an audition. He joins under strict conditions: family first, then studies, then music. He lands a shot at a world tour audition with legendary band member Yoon Dong-jin—but the stage ends in chaos due to a misunderstanding with his dad. Yi-chan, thinking Se-kyung loves bands, decides to perform at the school festival as a band.

To win Se-kyung’s heart, Yi-chan forms a band with former members of Bae-gwang High. They insist on recruiting Dong-jin as their guitarist. Yi-chan finally brings him from Chuncheon—only for the team to mistakenly identify Eun-gyeol, who is spotted on the streets of Hongdae, as Dong-jin. That night, among the homeless, Eun-gyeol finds a new sense of purpose in returning to the past.

Se-kyung becomes anxious about the appearance of Eun-gyeol, who seems to know her secret family history, and decides to leave Korea when the chance to study abroad arises. Meanwhile, Yi-chan discovers Cheong-ah trapped in a storage room being bullied. He gives her his contact info so she can ask for help—but Cheong-ah cannot speak or hear.

Eun-gyeol recalls a terrible accident his father once mentioned and sticks close to Yi-chan to prevent it. He challenges Hyun-yul to a band battle to help Yi-chan form his dream band. Just as they prepare for a vocal test, Se-kyung is rumored to have left to study abroad—but shockingly, she returns.

Back from the U.S., Se-kyung surprises everyone by being kind and straightforward to Yi-chan. Eun-gyeol grows confused by her behavior, while Yi-chan, caught up at the moment, changes the entire festival setlist to her taste—without discussing with his band member. Hurt and betrayed, Eun-gyeol has a conflict with Yi-chan.

Cheong-ah realizes that Yi-chan was the one who brought her to the hospital, and Yi-chan finally learns her name. He tries to reach out to Eun-gyeol, who has been missing for several days. Worried, Yi-chan is attacked by bullies while putting up flyers to find him. Meanwhile, Se-kyung secretly contacts each band member to confirm something, raising suspicions.

After being struck by lightning, Eun-gyeol wakes up in 2023—was it all a dream? He rushes home and tells his dad and Eun-ho what he experienced. While blaming his father for lying about his first love being Eun-gyeol’s mother, she suddenly walks into the room. His mother is Choi Se-kyung! Eun-gyeol begins to understand the true meaning of what the masters said before.

Shocked by a public confession, Yi-chan punches Eun-gyeol, accidentally giving him a nosebleed. Even the band members who try to break up the fight get caught in the chaos, resulting in a wild scene at the school playground. Eun-yu is also flustered by Eun-gyeol’s sudden confession. Meanwhile, through a series of events, Eun-gyeol uncovers Cheong-ah’s secret.

Cheong-ah starts learning sign language from Eun-gyeol, and Eun-yu grows jealous. Yi-chan is confused when Cheong-ah says they can still be friends. At Jonathan’s party, the band meets the legendary Yoon Dong-jin and learns that he has spite towards their band name, they boldly decide to change it. They boldly decide to change it.

As the school festival nears and the band prepares, Eun-gyeol recalls a crucial clue about the hearing loss incident. Believing Yoon Dong-jin is the “helper” the master mentioned, he tries to stop Yi-chan from attending rehearsal—but Yi-chan refuses. Eun-yu, shaken by her feelings for Eun-gyeol, starts to question who her mother’s true first love is.

Eun-gyeol, who remembers his promise to Eun-yu only after successfully preventing the accident, offers a belated apology—but she recalls memories of being abandoned and pushes Eun-gyeol away. Finally, the school festival begins, and the boys shout at the appearance of the goddess! Eun-gyeol and Yi-chan take the stage for a final showdown, each hoping to be chosen by Eun-yu. Who will she choose?

After the festival, Eun-gyeol and Eun-yu confirm their feelings and hope their time together will last longer. Meanwhile, the band must create their own song to enter the national youth band competition. Yi-chan proposes a song camp and considers how to involve Cheong-ah, who was recently hurt due to a misunderstanding.

Eun-gyeol and Eun-yu jump off the train en route to the song camp. Watching Yi-chan and Cheong-ah, the band members can’t help but feel a bit envious of the couple. Under Yi-chan’s leading, the radiant youths complete their song. Meanwhile, Meanwhile, another challenge awaits Cheong-ah.

Eun-yu gives Eun-gyeol a hint about Yi-chan’s hearing loss and promises to help him, as he continues to blame himself. While supporting him, she begins to question her relationship with Eun-gyeol and starts investigating people related to the incident. Meanwhile, Eun-gyeol gets a promise from Yi-chan not to leave the Snail House.

The two moons are beginning to appear. There isn’t much time left until the full moon. Eun-gyeol hesitates to return to 2023, torn between going back and leaving Yi-chan behind.