Although the word “overkill” can be used to describe practically any of Takashi Miike’s films, in some ways, the director’s brutal, 2 1/2-hour sword-fight fantasy “Blade of the Immortal” takes the notion to another level. For the ultra-prolific 56-year-old workhorse, his 100th feature is executed with “business as usual” craftsmanship. Miike’s first samurai film since “Hara-kiri: Death of a Samurai” (2011) and “Thirteen Assassins” (2010) marks a clear departure from the measured classicism of those two films. Instead, the story of a Wolverine-like swordsman with the capacity to self-heal delves into an aesthetic of pain, showing a twisted fascination in the hero’s bloody gashes and mutilations.

Despite the fact it stars evergreen super-idol Takuya Kimura (“2046”), the film earned a disappointing $6.73 million domestically. It should be more enthusiastically received abroad, with combined support from Miike’s staple extreme-action fans, and readers of Hiroaki Samura’s original long-running manga, whose English version was published by Dark Horse Comics.

Rumor has blamed the film’s limp box office performance on the controversy generated by recent disbanding of Japan’s most successful idol group SMAP, of which Kimura is the leading member. Whether that’s true or not, Kimura, or “Kimu-Taku” as he’s fondly called, looks suitably frazzled to play the world-weary protagonist Manji, doomed to eternal life for having killed 100 people.

The paradoxes of life and death, sin and redemption that underpin Samura’s manga are skimmed over in favor of a straightforward, action-driven story arc in Tetsuya Oishi’s script (he previously adapted the “Death Note” franchise). A moody black-and-white prologue provides a brisk backstory of how Manji’s sister Machi (Hana Sugisaka) was killed by bounty-hunters. After unleashing his wrath on Machi’s murderers, the injured Manji is involuntarily treated by a mysterious nun, Yaobikuni (Yoko Yamamoto), who uses blood worms to magically realign his veins and tissues.

A switch to color catches up with the protagonist in the mid-Edo period. Rin (also played by Sugisaka), daughter of kendo master Asano, stands helpless as the swordsmen of the Ikki-ryu school, led by Kagehisa Anotsu (Sota Fukushi), wipe out her father and all the students of his dojo. As she swears vengeance, Yaobikuni appears and advises her to hire Manji as her yojimbo (bodyguard). Although Manji finds the headstrong and bossy girl a pain in the neck, her uncanny resemblance to Machi exerts a hold on him.

Burdened with a manga that was serialized for 20 years and spanned 30 volumes, Oishi has effectively structured the plot around a series of one-on-one duels. Miike in turn peoples these fights with a colorfully grotesque gallery of adversaries, including the monk Eiku Shizuma (Ebizo Ichikawa), the prostitute Makie (Erika Toda) and Anotsu’s nemesis, Shira (Hayato Ichikawa).

Particularly memorable is Makie, who gets carried away when she’s on a slashing spree then sheds tears of remorse. Toda, who personifies a similar killing machine in the “Death Note” series, invests her bipolar personality with both campiness and poignancy. The dense plot also springs a few surprises, including a political conspiracy, a double-cross between kendo schools and a revelation by Shizuma which underscores the misery of being undead.

The story’s supernatural elements enable Miike to take huge liberties with chanbara, the oldest genre in Japanese cinema, and break free from rigid traditions of choreographing swordplay sequences — to the extent that the film’s free-form combat moves and creative, Gothic weaponry serve to accentuate the renegade spirit of Anotsu’s and Shira’s rival schools.

While the quasi-fantastical setting recalls Keishi Otomo’s popular swordplay trilogy “Rurouni Kenshi” (also executive produced by Hiroyoshi Koiwai), the coarse brutality of Keiji Tsuji and Masayoshi Deguchi’s stunts sets this film apart. Miike trades in the cartoonish style of his previous action extravaganzas (such as “Yakuza Apocalyse”) for a more graphic approach to violence, which includes stabbing, impalement and limbs flying everywhere.

In terms of casting, it’s clear that baby-faced Kimura is attempting an image makeover by playing a character who’s blind in one eye and crisscrossed with conspicuous scars and wounds. Beyond these outward appearances, however, the actor hasn’t reinvented himself through his performance, and is easily shown up by other more charismatic actors, including Ichikawa (in a short appearance, no less) and Fukushi, who expresses Anotsu’s moral duality with some emotional heft. Kimura and Sugisaka fail to generate enough chemistry to make Manji’s renewed will to live resonate. Though feisty enough in her role, Sugisaka falls short of the sensitivity and depth she brought to recent films “Her Love Boils Bath Water” and “Pieta in the Toilet.”

Keeping the action in tight closeups and medium shots, regular DP Nobuyasu Kita’s camera sometimes pulls back suddenly to reveal the carnage to stunning effect. While sets and locations in Kyoto are generic, Koji Endo’s restrained score makes the plaintive strings of the Japanese shamisen stand out at critical moments.