Terahashi, a science nerd who attends a preparatory school, spends his days being brutally bullied by his classmates. His only salvation is Natsu Tojo, an honor student who always protects him. For Terahashi, Natsu is a ``sanctuary (an angel) that must not be polluted'' who understands him, and his only purpose in life is to secretly take pictures of her and look at those photos. However, one day, Terahashi accidentally witnesses a scene that he should not have seen. It was Natsu having a secret meeting with Yamada, a married teacher, at school and having an affair. Feeling betrayed, Terahashi's romantic feelings for Natsu turn into a dark obsession. The next day, when Hanatsu Terahashi is called to the classroom after school...
