6 seconds of trajectory ~ The melancholy of fireworks artist Mochizuki Seitaro

In the summer of 2022, the COVID-19 pandemic was still ongoing, and the summer fireworks festival was announced to be canceled. Mochizuki Seitaro (played by Takahashi Issei), a professional firework expert, and his son A-Hang (played by Hashizume Ko) spent this year idly. A-Hang had suggested multiple times to Seitaro that although a large-scale fireworks festival couldn’t be held, they could take personal orders to put on small fireworks displays. However, Seitaro was visibly reluctant about this proposal. In order to prepare for personal fireworks displays, they would not only need to promote themselves online but also apply for a venue, and to meet customer needs they would have to conduct rigorous negotiations in advance, which Seitaro just didn’t feel interested in. In reality, the true reason he opposed the proposal was... One day, after having breakfast and tidying up as usual, Seitaro went to the workshop and found A-Hang collapsed on the ground, leaving behind a single apology before he stopped breathing. As winter arrived, Mizumori Hikaru (played by Honda Tsubasa) came to Seitaro with a handwritten flyer that read "Customized Fireworks for You" and asked him to help her with her fireworks. At that moment, for some reason, the deceased A-Hang suddenly appeared before Seitaro! Seitaro was taken aback, while A-Hang casually remarked, "Does it matter if you are dead or alive?"... Could he be a ghost?! Eventually, Seitaro agreed to help Hikaru, but when he asked what kind of fireworks she wanted, Hikaru replied that she wanted the most perfect fireworks in Seitaro's heart. On the day of the performance, Hikaru had an unexpected reaction to the fireworks, causing Seitaro’s heart to waver... What is Hikaru's true purpose in wanting to set off fireworks? How will the wonderful relationship between the Mochizuki father and son unfold?