Which Anime Uses Heartbeat As A Plot Device?

My heartbeat is so steady that sometimes, I don't resemble a human being at all. The fluctuations in my heart rate are very small even though I might be sleeping, suffering from a fever, or losing too much blood. When I'm 18 years old, the Ziegler family admits me into a rehabilitation center. My new home is now a temperature-controlled intensive unit located on the top floor. Oh, Aiden Ziegler doesn't love me at all. It's merely because the one and only artificial heart present in this world—and also in his chest—needs to be fine-tuned with my own heartbeat as its primary frequency. If my heartbeat is steady, he gets to live. If not, he dies. Three months ago, a nurse accidentally took off one of the monitoring pads on my chest. Five minutes later, Aiden, who was ten thousand miles away, went through a temporary crash where his heart stopped. The next day, the third-party medical company filed for bankruptcy. Everyone who was involved in this incident got banned by the medical world. Because of that incident, all of the sounds get eradicated from the top floor. Even the elevator's chimes get muted when it reaches the top floor of the rehab center. Everything changes when Aiden flies to Iropa. That's when his fiancee, Mandy Sutherland, takes over the rehab center. As she flips through my medical bill of nine figures, she sneers at me. "So, the Zieglers are basically sustaining a loser who does nothing but gasps for breath while lying in bed, huh?" After that, Mandy tears off the monitoring pads and unplugs the sync line. Then, she forces me to get on a treadmill. "That'll be a six-mile run for you. You can forget about returning to the top floor if you can't finish the run." As I grip the handrails tightly, I can feel my heart rate turning erratic for the first time ever. It feels as though my heart is about to burst out of my chest. As soon as the alarm goes off, Mandy turns it off immediately. What she doesn't know is that Aiden's artificial heart has already gone crazy, just like mine, while he's stuck in a place that's 12 time zones away.

She's an angel but he is a devil in disguise. Everyone says she attracts danger and she did by loving him. A night together and they started to crave each other even more. The devil has his secrets deeper than death and the days she loves him is the day they will be separated. The love which started in a heartbeat can also end in a heartbeat, right?

When Aiden Gomez, the heir of Gomez Robotics Company, is shoot to death by their family's mysterious traitor and falls into a coma, his scientist grandfather creates an artificial intelligence humanoid robot to take his place. His name is Aiden 2.3 who looks exactly like the human Aiden. In the middle of their mission, Enzo Romeo, a good-humored programmer, find himself falling in love with Aiden 2.3 whose robotic and programmed heart starts to beat like a real human. "What kills people are their personal ambitions."

After my rebirth, the very first thing I did was ride from one blood donation van to another, giving blood until I nearly collapsed. Why? Because in my previous life, my fiancé's newly hired intern, Shirley Lynch, had bound herself to a blood-exchange system. Every milliliter she donated was siphoned directly from my own veins. In just a month, she transformed from an ordinary college girl into the nation's beloved Blood Angel, showered with fame and fortune, while I, suffering from severe anemia, was fired from the hospital for being unable to work. When I exposed her scheme to my fiancé, he looked at me with disgust and broke off our engagement. "You're selfish and cowardly," he sneered. "You refuse to donate your rare blood type, and now you slander Shirley? You call yourself a doctor, yet you believe in such ridiculous nonsense!" From then on, every time Shirley donated blood, I would suffer heart palpitations, dizziness, and sometimes collapse outright. I begged the doctors in my department for help, but my fiancé blocked every attempt, accusing me of jealousy and wasting medical resources. In the end, to steal my promotion ahead of schedule, Shirley donated a full 1000 milliliters of blood live on television. As her blood drained, so did mine. I went into shock and died. When I opened my eyes again, I was back on the very day Shirley first claimed she carried my rare blood type.

When the nurse pulled the IV needle out of the back of my hand, her gaze was filled with pity. “Mr. Young, the heart meant for your transplant was transferred at the last minute. It was sent to the VIP ward on the seventh floor. It’s a shame, but all your pre-operation prep has gone to waste.” Marcus Stewart was warded on the seventh floor. He was the frail young man my sister brought home. Ten minutes ago, Marcus suddenly had terrible chest pain. My usually strong mother burst into tears. My stoic father slammed the table in front of every expert in the hospital, then decided to give Marcus the heart I had been waiting three years for. It was supposed to save my life. I hurried to the end of the corridor, but the green operating light had already come on. Clutching the twisting pain in my chest, I leaned against the ice-cold wall and slid to the floor. There was no need to wait anymore. My heart failure was terminal. The doctor said I would not last the next few days. The mechanical voice sounded in my head. [Master, your vital signs are rapidly deteriorating. If you terminate this body and leave this world now, you still have a chance at a new life. Would you like to proceed?] I looked at the faint grey hue of death tinging my fingertips. “...Yes.”

In the neon-drenched shadows of Nairobi, Alessia wakes from a fatal gunshot with a chilling clarity: she is not who she thinks she is. While her lover, Mafia heir Lorenzo, mourns the woman she was, Alessia’s body begins to "remember" lethal skills, ancient languages, and violent deaths she never lived. She is Subject A, a high-velocity asset in Project Déjà Vu, a global conspiracy by the shadowy organization VANTA. As the "Blood Memory" fractures her reality, Alessia discovers a horrifying cycle: she and Lorenzo have been paired across centuries, engineered to fall in love only to be reset through state-sponsored tragedies. Their "Affinity" isn't fate—it’s a biological battery used to harvest emotional resonance and destabilize world power structures. Every time they grow too powerful, the system triggers a "Liquidation," wiping their minds to begin the loop anew. But this time, the glitch is permanent. Alessia evolves into the Perfect Weapon, accessing the tactical archives of her past iterations. To break the cycle, she makes the ultimate sacrifice: she severs her connection to Lorenzo, choosing cold, calculated vengeance over manufactured love. While Lorenzo unleashes his own buried rage to protect her, Alessia goes rogue, infiltrating VANTA’s core to delete the "Failure Cycle." As she nears the Creator, Silas, she faces a devastating truth: they weren't just assassins, but prototypes for a global replacement of the elite. To win her freedom, Alessia must decide if she can ever truly love the man who has been her executioner for three hundred years. The loop is breaking, the system is crashing, and the blood is finally speaking. "The memory is in the marrow. The revenge is in the soul.”