Tobe Seito no Namae Kurai Oboero-gou

"I don't hate anybody, and nobody hates me. I'm just really pissed off." Gloomy high school student Sugino meets a girl on the school's roof. "You should write down all your gripes and anger on paper, and then bring them to me." Hearing this, Sugino starts writing... (Source: Kodansha, translated)