Fanon / Inuyasha

• Sesshomaru is the Lord of the West, and he has a manor, home, or castle somewhere with servants and subjects. This fanon is sometimes expanded into a full demon hierarchy with numerous daiyoukai ruling other areas of Japan (Koga is a popular candidate for one). In the actual series he's a nomad with no established home, he's not the ruler of any land, only becomes a daiyoukai at the end of the story, and his only servants are the ones you see with him all the time - and those mostly seem to have latched onto him in spite of his preference. This seems to have originated with sketchy fan translations that his father was a youkai "who prowled the west". Sesshoumaru's mother does live in a palace that travels through the sky, but even Sesshoumaru is only an occasional visitor who struggles to locate it, and she was introduced years after the fanon became established.
  • In fact, even Sesshomaru's father never bore any such designation, either. He is only ever called "Inu no Taishou", and while this would translate as "Dog General", in spirit the title could be much more broadly interpreted, which the English version wisely represented with the more ambiguous "Great Dog Demon". He is never explicitly stated as having "ruled" the West, only to have resided there.
• In the absence of any Canon Names for them, it's common to see Inuyasha and Sesshumaru's father referred to in the English-speaking fandom as "Inutaisho" (a corruption or mishearing of "Inu no Taisho"). Less accepted but still present is the idea that his name is "Toga", a name that the production team on the third movie gave him. But they only gave it to him for the sake of having a proper name to call him by among themselves; no name is ever mentioned in the finished film.
  • Sesshomaru's mother is popularly called "Inu Kimi" (sometimes "Inu Kami"; the former, though more common, is probably a misspelling of the latter, which is Gratuitous Japanese for "Dog God"). The third movie specifically names Inuyasha's mother "Izayoi," and this is almost universally accepted.
• Hand in hand with the very common plot of "the youkai of the feudal era survive to the modern day", as well as countless Alternate Universe stories, is the idea that charms exist to mask youkai and youki so they can pass as normal humans; rings are the most common item for this. In the actual series, no such spells exist. In fact, it's heavily implied, if not outright stated, that only the most powerful of youkai can take on humanoid forms in the first place.
• Many fans are set on the fact that Inuyokai, and canine/vulpine youkai in general, are very into stock tropes of canine behaviors — they have pack dynamics with alphas and betas, they prefer to have sex on all fours, and they "mark" their mates with a bite on the neck or breastbone. Exchanging scents, grooming each other, sleeping together (in the literal meaning, curled up on a pile), and even semi communal raising of children, also occur occasionally. They may also go through animal-based mating seasons (and yes it's almost always the male dog or wolf youkai that "go into heat").
• It's common to see youkai able to transform their human "mates" into hanyou or even full-blooded youkai, usually by the mating process or through a blood transfusion (or both). In the canon there are two instances of a human turning into a hanyou or youkai, and those two instances are Naraku and a Filler character named Sara, who did so through highly unique and usual means and they just became hanyou (Naraku's evolutions aside). Nothing in the canon supports the idea of a human becoming a hanyou or youkai through any sort of mating ritual or blood transfusion. This is once again an Acceptable Break from Reality to avoid the inevitable conclusion of the Mayfly–December Romance between Inuyasha and Kagome. Some works may dial this back to the human's life just being extended by continual transfusions of youkai blood, not actually transforming them or granting them an equivalent lifespan.
• If fanfiction ever deals with Kagome growing older, she'll likely become some sort of doctor due to her experience patching up her friends. In The Final Act she is seen learning herbalism from Kaede so she'll likely become the village healer.
• Inuyasha's tranformation to full youkai being triggered by anger. In canon it’s triggered by fear of dying, not anger; the Unstoppable Rage comes afterwards.
  • In the same vein, him being shirtless as a full youkai — even though the only time he was shirtless as a full youkai was the first time we see him access that form.
• Many fans assume that Jinenji is a horse hanyou because his face looks elongated and horse-like. But actually this assumption in the canon is neither confirmed nor rejected.
• Jaken is universally believed to be serving Sesshoumaru as a result of a life-debt he owes him. The source of this belief comes from a random stand-alone filler episode the anime did that attempted to pad out Jaken's background. The original manga doesn't explore Jaken's background at all and never explains why he serves Sesshoumaru.
• Inuyasha is popularly cited as being 200 years old. This comes from the third film adaptation and not from the original manga.
• Multiple types of Inuyoukai are popular as well, frequently including silver/white, black, and red, sometimes with different social standings and culture depending on the color.