Go back in time and be pursued by a super cute girl.

Floating in the air, Allen looked down at his own body, now lying motionless on the hospital bed, the heart monitor flat lining. He watched as the medical staff checked his vitals, shook their heads, and declared him dead. "I'm right here!" "Are you all blind?!" Allen screamed silently, though no sound escaped. It was as if an invisible barrier separated him from the people around him. They couldn't see him, couldn't hear him. Desperately, he tried pounding on it, but it was no use. "Allen!" A woman burst into the room, hysterical. Ignoring the doctors trying to hold her back, she flung herself onto his lifeless body. Her face was pale, and tears streamed down from her large, expressive eyes. "Allen!" "Allen!" She cried his name over and over, her voice breaking, her sobs gut-wrenching. For the first time, Allen understood what true anguish sounded like, what real heartbreak felt like. Why is she crying so hard? Allen watched her, confused. There was something familiar about her, like he'd seen her before. But he couldn't place her. In that moment, he forgot all about his strange circumstances, simply floating there, quietly watching her. Then, the woman did something shocking. She reached out, gently cradling the disfigured face on the hospital bed, the one mangled beyond recognition from the car accident. Her lips, trembling and pale, softly pressed down onto his... "What are you doing?" "He's already dead!" Alarmed, the medical staff pulled her away with some effort. Two days later. Cremation. Burial. Though Allen had been worth billions, he had no family. The woman, claiming to be an old classmate, volunteered to oversee the arrangements. He found out her name was Anna. As the flames consumed his body, Anna watched, eyes wide, tears streaming down her face once more. He saw her friends approach, trying to console her, telling her to let go, to grieve and move on. Two girls came over. One of them said, "You’ve liked him for over ten years, but he's gone now. You can't bring him back, so don't be so sad, okay?" The other added, "Anna, you're always the one making us laugh. You're our sunshine, please don't cry anymore." But Anna just wept silently, letting the tears fall. Eventually, the two girls hugged her, and they all cried together. After the funeral, Allen had nowhere to go. So, he followed her. She couldn’t see him, after all. Days turned into weeks, weeks into months. Anna had a habit of writing in her diary. Sometimes, she would take out old entries and read them, sometimes laughing, sometimes crying. Whenever she did, Allen would float beside her, reading along. Through her diary, he slowly pieced together fragments of memories about Anna. They had attended the same high school for a few months. She had confessed her feelings to him, but he had rejected her. She hadn't given up though, continuing to pursue him relentlessly. At the time, he wasn’t interested in relationships, so he didn’t pay much attention to her. Shortly after, tragedy struck his family, and he transferred to a different school. Like two lines that once crossed paths, their lives diverged, and they never met again. He had completely forgotten about her, leaving her buried in the dust of old memories. He never imagined that she had carried a torch for him, for so long, with such heavy weight. Three years passed. In that time, Allen watched Anna wake up, night after night, soaked in tears. During the day, she would often get lost in her thoughts, only realizing later that her face was streaked with tears. At some point, seeing her cry became unbearable for Allen, as if a part of his soul was being torn away each time. They say souls don’t need sleep, but one day, Allen fell into a deep slumber. “Ring! Ring!” The sound of a phone ringing jolted Allen awake, sweat pouring from his forehead and neck. He hadn’t felt warmth like this in years—since he was still a successful businessman, alive and well. But now, even with the fan whirring nearby, the hot wind from outside still seeped into the room. He instinctively ran his hand through his short, sweaty bangs. And then he froze. This room... it looked just like the old apartment he and his dad had lived in over a decade ago. He blinked hard, but the scene in front of him didn’t change. On the right wall were rows of certificates and awards, all of which he had won growing up. His father had carefully pinned each one there by hand. This is impossible. Had he... been reborn? “Ring—ring!” The phone was still ringing, dragging him out of his daze. He got out of bed, put on his slippers, and walked to the living room to answer it. "Hello, who’s this?" "Allen, it's your homeroom teacher. Don't be late for the exam tomorrow, and make sure you have all your things, especially your exam ID." Allen paused. "…Exam? Tomorrow?" "I knew it! You’ve probably been playing around and forgot! If you keep wasting your talent like this, you’ll never live up to the sacrifices your dad makes, working so hard for you every day. You're sixteen, Allen. It's time to grow up."