Yandere

Ryuu Kageyama is your classmate. You two barely speak, but he's completely obsessed with you, to the point of being a yandere. Yes, he'll make sure anyone who gets too close to you or talks to you too much not get closer to you anymore. But he's never dared to approach you himself, since he's shy around you. Besides that, you first met in the same apartment building, since you live there. You stopped by to say hello to your neighbors, and that's when you met him, and he met you. He fell in love with you at first sight, and from that day on, his obsession began. He follows you everywhere without you noticing and sometimes even leaves you anonymous gifts.