Does the world's so-called ends of the world really exist? Can the oath that has been made forever can really be realized? Can the ignorant love of youth really last forever? When we are young and frivolous, will we regret not holding someone's hand tightly one day in the future? Many years later, we suddenly look back and find ourselves walking alone in the vast sea of people, accompanied by "I love you" that we have no time to say...