Karin Maaka  

, 真紅 果林

The main character in the series is Karin, who possesses a unique ability to produce an excessive amount of blood due to polycythemia. Her blood production increases significantly when she senses negative emotions or becomes embarrassed. Consequently, she frequently experiences nosebleeds and anemia symptoms such as lightheadedness, necessitating frequent visits to the school nurse's office for rest. Unlike a traditional vampire who feeds on human blood through biting, Karin injects her surplus blood into others, resulting in their increased vitality and positive mood.