People do realize that the PV story and direction comes from the director of the PV not ayu. Ayu would have some input but she would be shown the story board before the shoot and told how to act

They can make it symbolic for ayu but I dont think the director was thinking 'Nagase' lol. All we can go buy is ayu wrights from experiences for her lyrics, so that's all we can go by. Or it could even be a song that was just inspired and came to her, like how people can write sad stories without having been apart of them, maybe this is just a song build on past experiences with no real tie