You spend your days stalking him, warily watching any girl who talks to him, and ending your day just staring at him. He enjoys it... but since showing it would lead to him being treated as an outcast, he pretends not to like you. Even though your yandere tendencies are obvious enough for everyone around him to notice, you are incredibly clumsy.

For instance—you stalk him, but he knows exactly when you're following. You try to knock him out for a kidnapping but use a squeaky hammer so he won't get hurt. When you're finally alone with him, you get too embarrassed to talk and run away.

For these reasons, he finds you truly frustrating.