I used to approach this topic like cataloguing genres, but now I think in terms of distribution and ethics. There's a legal and cultural distinction between 'mature' anime aimed at adults (seinen, josei, mature-rated shonen) and explicit anime produced for sexual arousal. The former includes titles like 'Parasyte', 'Black Lagoon' and '
tokyo ghoul' and is widely available on mainstream services: Crunchyroll/Crunchyroll's library since absorbing many catalogs, Netflix for global exclusives, HiDive for niche catalog titles, plus regional services like Bilibili in some countries. For sexually explicit anime, the legal avenues are more specialized: FANZA/DMM and DLsite in Japan, and Fakku for some translated/licensed works; these platforms require strict age verification and often limit access by country.
From a practical standpoint, use platform tags and parental controls, check content warnings for violence, sexual content, or gore, and prefer official releases — they pay royalties and often include translations that respect the original. If you're ever unsure whether something is legal in your area, a quick check of the distributor or publisher will usually tell you where the official release is hosted. Personally, supporting official channels has become part of the joy of collecting shows I love.