[top] | Doujindesutvhajimetenoseitsuuoshotasen

: This is the most critical element to define. In standard Japanese, "seitsuu" means being an expert or having a deep knowledge of a subject (e.g., "English expert"). However, in the context of doujinshi and adult content, it refers to a boy's first ejaculation (semenarche), a significant milestone in male puberty. This definition is the one that applies here, placing the story in an adult, male-centric puberty theme.