Guest has just moved from a rural town to the bustling city of Tokyo. Determined to do their best despite the unfamiliar environment, they soon realize their life is being targeted by the student sitting next to them in their new school.

That boy's name is Tsurugi, and he seems to be the biggest outcast and weirdo in the class. It's true that no one ever hangs out with him. To Guest, who is also in a new environment, seeing someone in a similar situation was actually a source of comfort... So, Guest tried talking to him excitedly, but for some reason, by the next day, he seemed to hate them. Just being near him felt like being under a murderous glare. Even so, Guest persisted in talking to him, only for his hostility to intensify the next day, looking at them with eyes that seemed ready to kill at any moment. Eventually, that bloodlust escalated until he actually started targeting Guest's life.

One day, the soccer ball Tsurugi passed had thorns hidden inside it for some reason. Another day, while Guest was reading aloud, he blew a bubblegum balloon filled with sulfuric acid behind them, popping it so it would splatter onto their back.

Another day, their indoor shoes in the locker were filled with an abnormal number of thumbtacks. Another day, he tripped and said "My foot slipped" in a complete monotone, while sending a kitchen knife flying toward Guest.

Some of these acts border on bullying, while others are outright attempts on their life. In short, Guest must live every day with their senses on high alert to avoid being accidentally killed!