
Anime are primarily classified by demographics (target audience) and genres (themes). The five main demographic groups are: Shounen (action for young people), Shoujo (romance/drama for young people), Seinen (adult themes), Josei (adult drama for women), and Kodomomuke (children's). Popular subgenres include Isekai (alternative world), Mecha (robots), and Slice of Life (slicee world), Mecha (robots), and Slice of Life (slice-of-of life).
Shounen: Aimed at a young male audience (8-16 years old), focusing on action, adventure, and friendship. Examples: Naruto, One Piece, Dragon Ball. (Obs.: shōnen (少年) is the Japanese word for "boy" or "youth," typically referring to males under 20 years old.)
Shoujo: Aimed at a young female audience (8-16 years old), focusing on romance, emotions, and school settings. Examples: Sailor Moon, Sakura Card Captor.
Seinen: Aimed at adult men (18+), with denser, psychological, or violent stories. Examples: Berserk, Vinland Saga, Death Parade and Akira.
Josei: Aimed at adult women (18+), portraying mature relationships and everyday life. Examples: Paradise Kiss, Usagi Drop.
Kodomomuke: Children's anime (0-9 years old), with educational and cute themes. Examples: Hamtaro, Pokémon.
Isekai: Protagonist transported or reincarnated in another world. Ex: Sword Art Online, Campfire Cooking in Another World with My Absurd Skill.
Mecha: Giant robots and futuristic technology. Ex: Neon Genesis Evangelion, Gundam.
Slice of Life: Focuses on the simple daily lives of the characters. Ex: K-On!, Clannad.
Fantasy/Action: Magical worlds and battles, very common in Shounen. Ex: Demon Slayer, Hunter x Hunter.
Horror/Suspense: Focused on fear and mystery. Ex: Death Note, Another.

Filler in anime means episodes or arcs not in the original manga or novel. They pad runtime, add side stories or comedy, and usually don’t advance the main plot, so many fans skip them without losing key story points.
OVA (Original Video Animation): Anime released directly to home video, without television broadcast.
ONA (Original Net Animation): Anime released directly on the internet.
Ecchi: Content with mild sexual appeal, aimed at comedy. Harem: A protagonist surrounded by several love interests.
One anime can be framed within an almost limitless combination of genres, sub-genres, and demographics, often blending three to five or more distinct categories simultaneously. Because anime is a medium rather than a single genre, creators frequently layer multiple themes, resulting in complex classification.
Fullmetal Alchemist is primarily classified as an adventure, dark fantasy, and steampunk action series. As a popular shonen series, it blends elements of science fantasy and drama, following two brothers on a quest for the Philosopher's Stone to restore their bodies after a failed alchemical experiment.