TVアニメ『小林さんちのメイドラゴン』オリジナルサウンドトラック「小林さんちのイシュカン･ミュージック」

In music taxonomy, "seinen" refers to songs and scores associated with anime and manga aimed at young adult men (seinen). In practice, it is not a single musical idiom but a programming tag that gathers opening/ending themes, character songs, and background scores from series serialized in seinen magazines or targeted to older teens/adults. Stylistically, seinen music spans two prominent poles: - Mature, moody soundtracks and themes for psychological thrillers, cyberpunk, crime, historical, or military dramas. These often blend alternative/indie rock, post-rock, electronic (IDM/synth/industrial), and cinematic orchestration. - Light, character‑driven pop for slice‑of‑life or "moe" titles aimed at adults, featuring seiyū (voice actors) singing bright J‑pop or idol‑style songs with tight hooks and glossy production. Because of this breadth, "seinen" is best understood as an application context for anisong and Japanese popular styles, rather than a narrowly defined genre with fixed musical rules.