A detailed spoiler breakdown reveals key plot twists and resolution:
- Ha Yi-chan was not born deaf: Eun-gyeol discovers in 1995 that his father was a fully hearing teenager who lost his hearing due to an accident at age 18.
- Choi Se-kyung’s Identity: The girl claiming to be Choi Se-kyung in 1995 is actually On Eun-yoo, her daughter from 2023 who time-traveled via the same music shop.
- The Altered Accident: Eun-gyeol successfully prevents the original rehearsal room accident. However, on the day before his return to 2023, a drunk driver targets Eun-gyeol; Yi-chan pushes Eun-gyeol out of the way, taking the impact himself and losing his hearing as a result.
- Exposing the Abuse: Eun-gyeol and Yi-chan expose the abusive stepmother's mistreatment of Cheong-ah to Chairman Yoon of Jinsung Group, freeing Cheong-ah and restoring her legal status.
- The New Present (2023): When Eun-gyeol returns to 2023, his father is now the successful CEO of Jinsung Instruments, his mother Cheong-ah is the Chairwoman of Jinsung Group, and his family lives in abundance and joy. Eun-gyeol performs freely as a guitarist on stage with his father watching proudly in the audience.