Anyone who thinks blood is thicker than water hasn't watched enough anime. The style is loaded with familial brawls, some of which are among the best anime final fights of all time. Because the adversaries share a genetic bond, their issues usually run deeper than the immediate moment, which makes most anime sibling fights feel especially vicious.
In Naruto, Sasuke's attempt to exact revenge on his brother Itachi is incredibly memorable. The pair's final encounter features notably stunning choreography and gorgeous animation, and the potent mixture of love and hatred that exists between the brothers elevates the moment to a new level.
When two relatives square off after a lifetime of disagreements, the resulting fight always carries an additional layer of meaning.
Inuyasha and Sesshomaru do not get along, and their issues have little to do with their differing personalities. Inuyasha is half-demon, half-human, which causes the pure-blooded Sesshomaru to view him as genetically inferior. The brothers' relationship worsens after their father decides to give each of them a sword; Inuyasha gets the more powerful blade, which enrages the proud Sesshomaru.
During the pair's most dramatic clash, Sesshomaru attempts to take possession of Inuyasha's sword and inadvertently buries Kagome in poison. However, Inuyasha's pledge to defend Kagome unlocks his sword's latent abilities, as it was originally crafted to protect humans (like Inuyasha's mother). This allows Inuyasha to finish the fight and defeat his brother.
Vash and his twin brother Knives are Plants, humanoid creatures who are cultivated like resources, then cruelly discarded when their usefulness subsides. Understandably, neither brother is particularly thrilled about this, but Knives takes his reaction to another level. Hungry for vengeance, Knives decides he wants to wipe out the human race.
Since Vash still cares about humanity, he finds Knives' plan drastically cruel, which places the siblings on opposite sides of a difficult impasse. The brothers engage in a massive battle that leaves both gravely injured. After the fight concludes, Knives' fate has left a mystery.
When Olivier Armstrong returns home, she tries to pressure her elderly father into retiring, so she can take control of the family's affairs. Her father refuses, as he allegedly intended for her brother Alex to succeed him. To settle things fairly, the patriarch asks his children to fight over the responsibility.
The resulting fight could have been dramatic, but instead, it's played for laughs, which makes it incredibly memorable. While Olivier and Alex throw each other into walls, the rest of the family calmly packs for a vacation to Xing.
Olivier is the victor, but this assumedly means she's the one who has to pay for the damage their father's house incurred.
As a young child, Akame is separated from her sister Kurome so they can both learn to stand on their own as strong warriors. The girls eventually become swords for hire but end up working for opposing factions - Akame sides with the Night Raid, and Kurome with the Jaegers. This all leads up to a sword fight of epic proportions.
To maintain her energy, Kurome is dependent on performance-enhancing substances, so she isn't able to match her sister's skills when the effects start to wear off. The fight is ultimately stopped by Wave, another Jaeger member who declares his love for Kurome and suggests they defect together. Kurome agrees to leave the Jaegers behind, and the sisters are able to reconnect on friendly terms later in the series.