First airing in 2000, Inuyasha delivered a successful isekai anime series well before the term "isekai" became commonly used. Considered one of the most popular gateway anime to introduce new viewers to Japanese media, the series implemented many classic isekai tropes fans enjoy today.
While it's not the first or oldest anime that can be defined as such, it was the first isekai for many. Here's how Inuyasha made anime viewers fall in love with the isekai genre -- before it was even defined.
Inuyasha: Action and Adventure in a New World
Like most isekai anime, Inuyasha stars a protagonist who is suddenly transported to a different world or era far from her own. Kagome Higurashi is a high schooler living in modern-day Japan at her family's Shinto shrine, until she's suddenly dragged into the shrine's Bone Eater's Well while looking for her cat. After being forced into the unsuspecting well by a demon, Kagome finds herself falling through time and arriving in Japan's Feudal Era, where demons and the supernatural thrive. The anime's premise follows the typical isekai formula of a character being transported or reincarnated into a new and unfamiliar world, allowing audiences to explore and learn about the fantasy world alongside the protagonist.
While isekai provides a new realm to be explored, action and adventure become the primary ways for characters to grow familiar with their surroundings. Whether it's a virtual world like No Game, No Life or a fantasy world like Kamigami no Asobi, isekai uses the thrill of adventure to journey across the new world while characters interact and learn about its greatest secrets.
Inuyasha heavily relies on adventure after Kagome and Inuyasha meet and agree to find the Shikon Jewel shards together. During their journey, they meet many magical and valuable friends like Miroku the monk, Shippō the kitsune yōkai, Sango the demon slayer, and Kōga the wolf yōkai. With every new person they meet and territories they explore, the cast and viewers learn more about this supernatural Feudal Era and how its magic works. This important adventure element of isekai provides intricate world-building that fully submerges viewers into its fantastical story.
Alongside the epic adventure that has become a genre hallmark, isekai is also known for its action-packed animation and storylines. As their predecessor, the sword-swinging action in Inuyasha was later found in extremely popular isekai series like Sword Art Online and The Rising of the Shield Hero. Swords are the primary weapon of choice, offering stylistic combat and unpredictable moves that hypnotize viewers. Inuyasha focuses on the power and importance of swords as well, with Inuyasha and his older brother Sesshomaru constantly fighting over their deceased father's legendary swords that can either take a life or save one -- the Tenseiga and Tessaiga. These action-heavy isekai anime are enjoyed by a large demographic because they add a thrilling and suspenseful escape within their fantasy worlds.
Isekai's Fantasy Romance Across Worlds
The most popular isekai anime have a strong romance element and Inuyasha is no exception. While isekai transports characters to new worlds, they often find love in unexpected ways. As forbidden and fantasy romance continues to rise in popularity, so does the genre that sets the stage for otherworldly love. Isekai anime like Is It Wrong to Try to Pick Up Girls In a Dungeon? and The Devil Is a Part-Timer explore the love between humans and deities, with fateful bonds that couldn't occur outside the genre. These series allow anime to spotlight fantasy romance between human and non-human beings, like the demons and creatures found in Inuyasha.
While Inuyasha is much more than a love story, its strong focus on love and friendship is one of its most endearing qualities. As Kagome learns to fall in love with a rowdy and angsty half-demon, Inuyasha learns how to love a bossy yet fragile human whose time is fleeting compared to his own lifespan. While their bonds strengthen around their traveling friend group, Sango and Miroku become two humans with unnatural combat abilities who also find improbable love.
Exciting plot twists and extreme character development also come into play when Sesshomaru, who once despised humans and his brother for being half-human, comes to value and protect a mere human girl with his life. With drawn-out romance and intricate character development throughout, Inuyasha viewers receive in-depth storytelling that makes them emotionally invested in the characters.
With popular isekai running the current anime market, Inuyasha offered the ideal template for future series to build from. While it wasn't the first series that could be defined as isekai, Inuyasha was the most prominent and influential anime to familiarize viewers and set the standard for the genre. As more isekai anime come to fruition, they each owe a debt of gratitude to their predecessor that helped pave the way for the genre -- before it even got started.