《鬼滅之刃 特別編輯版 那田蜘蛛山篇》是由外崎春雄執導、ufotable製作，並於 2020 年10 月 17日上映的日本動畫電影。這部特別編輯版將漫畫原作吾峠呼世晴第四卷至第五卷的內容，也就是電視動畫《竈門炭治郎 立志篇》第 15 集至第 21 集，重新剪輯成大銀幕版本，並針對畫面與節奏進行調整，使觀眾能一次性體驗「那田蜘蛛山」的重要戰役。

故事背景發生在炭治郎與同伴擊敗前任「下弦之陸」響凱之後。經過短暫的休養，他與我妻善逸、嘴平伊之助一同接到新任務，被派往那田蜘蛛山支援作戰。這座山上居住著一個擁有蜘蛛能力的鬼族家族，並傳聞其中潛藏著「十二鬼月」的成員。當三人抵達時，情況已經相當嚴峻，原本奉命組成的討伐隊大多數隊士皆遭到蜘蛛鬼「母親」以血鬼術操控絲線，反過來自相殘殺。炭治郎與伊之助在危機中聯手，最終擊敗蜘蛛鬼「母親」。臨死前的「母親」透露，在這座山中確實有十二鬼月的存在，這讓炭治郎一行人更加警覺。

同一時間，鬼殺隊當主產屋敷耀哉從先遣部隊的情報得知狀況嚴重，便派出鬼殺隊最強戰力之一的兩名「柱」——水柱富岡義勇與蟲柱蝴蝶忍前往增援。

另一方面，善逸因得知炭治郎將妹妹禰豆子帶入山中，為了保護她而冒險進入，卻不幸遇上蜘蛛鬼「哥哥」，並因對方的毒素而陷入險境。在命懸一線時，他回想起師父慈悟郎的教誨，突破自我，創造出「雷之呼吸 六連」的新招式，成功擊敗「哥哥」。不久後，重傷的善逸被蝴蝶忍救下並帶走治療。

此時，炭治郎與伊之助則遭遇蜘蛛鬼「父親」。伊之助雖拼盡全力砍下對方手臂，但「父親」竟能迅速再生，甚至蛻皮進化成更強大的第二型態。伊之助在苦戰中幾乎被掐死，幸好富岡義勇及時趕到，瞬間將「父親」斬殺，並判斷伊之助因重傷無法再戰，將他暫時制住以免送命。

炭治郎另一邊則遭遇蜘蛛鬼「姊姊」與「弟弟」。他很快察覺「弟弟」所謂的「羈絆」其實是建立在恐懼與支配之上，並非真正的家人之情。在戰鬥中，炭治郎陷入劣勢，眼看就要被「弟弟」的絲線斬殺時，禰豆子挺身而出，展現她與哥哥之間的真正羈絆。這份情感甚至讓「弟弟」——真正身份是十二鬼月「下弦之伍」累——動了奪取禰豆子的念頭。炭治郎拼命抵抗，卻連「水之呼吸」最強的招式都斬不斷累的絲線。就在危急時刻，他想起父親曾教導的「火之神神樂」，與此同時禰豆子覺醒血鬼術「爆血」。兄妹兩人合力斬下累的頭顱，卻發現累早已用絲線分離頭顱逃過一劫。就在累準備憤怒地殺死兩人時，富岡義勇現身，以壓倒性的實力結束這場戰鬥。

臨死前的累回想起過往，想起自己在生前對父母滿是愧疚與悔恨的回憶。他逐漸理解自己所追求的「羈絆」其實是錯誤的，靈魂在地獄中與父母重逢，最終一家三口在烈火中相擁而泣，隨著業火一同消逝。至於蜘蛛鬼「姊姊」，因累給予最後機會要求她殺更多鬼殺隊成員，她試圖襲擊村田卻被蝴蝶忍攔下。面對絕對的實力差距，她懇求寬恕，卻被蝴蝶忍識破謊言，最終被其親手以毒擊殺。

在故事最後，當義勇保護炭治郎與禰豆子時，蝴蝶忍認為義勇偏袒鬼，因而與他對峙。炭治郎則帶著禰豆子逃走，途中遇到同期隊士栗花落香奈乎，眼看就要被她斬殺時，鬼殺隊總部下達「活捉炭治郎與禰豆子」的命令。待炭治郎醒來，他已經被帶到產屋敷宅邸，並置於眾柱面前，為後續故事揭開新章。

本片全長138分鐘，透過劇場版的形式，將那田蜘蛛山的戰役以更加緊湊且壯闊的方式呈現，既保留動畫的張力，也加深觀眾對炭治郎兄妹羈絆的共鳴。這場戰鬥是《鬼滅之刃》劇情中的轉折點，不僅首次讓炭治郎與十二鬼月正面交鋒，也揭示「羈絆」真正意涵與角色心境的對照，成為粉絲心中極具代表性的一幕。

“Demon Slayer: Kimetsu no Yaiba – The Movie: Natagumo Mountain Arc (Special Edition)” is a Japanese animated film directed by Haruo Sotozaki and produced by ufotable, released on October 17, 2020. This special edition re-edits the events from Koyoharu Gotouge’s manga volumes 4 and 5—corresponding to episodes 15 to 21 of the TV anime’s Tanjiro Kamado: Unwavering Resolve Arc—into a cinematic format. The visuals and pacing were adjusted to allow audiences to experience the pivotal “Natagumo Mountain” battle in one continuous film.

The story begins after Tanjiro Kamado and his companions defeat Kyogai, the former Lower Rank Six of the Twelve Kizuki. Following a brief rest, Tanjiro, along with Zenitsu Agatsuma and Inosuke Hashibira, are dispatched on a new mission to support demon slayers fighting at Natagumo Mountain. This mountain is inhabited by a family of spider demons, and rumors suggest that a member of the Twelve Kizuki lurks there. By the time the trio arrives, the situation is dire: most of the original demon slayer squad has already fallen, manipulated by the Spider Mother’s threads into killing one another. Tanjiro and Inosuke join forces and succeed in defeating her. With her dying words, she confirms that a Lower Rank of the Twelve Kizuki resides within the mountain, raising the stakes even further.

Meanwhile, the Demon Slayer Corps leader, Kagaya Ubuyashiki, upon receiving urgent intelligence from the frontlines, dispatches two elite Hashira—the Water Hashira Giyu Tomioka and the Insect Hashira Shinobu Kocho—to provide reinforcements.

Elsewhere, Zenitsu, realizing that Tanjiro has brought his sister Nezuko into the mountain, rushes in to protect her. Unfortunately, he encounters the Spider Brother demon and falls victim to its poison. On the verge of death, Zenitsu recalls his master Jigoro Kuwajima’s teachings, overcomes his limits, and unleashes a new technique: Thunder Breathing, Sixfold. With this breakthrough, he defeats the Spider Brother. Gravely injured, Zenitsu is later saved by Shinobu, who tends to his recovery.

Tanjiro and Inosuke, on the other hand, face the formidable Spider Father. Inosuke fights valiantly, even managing to sever his arm, but the demon regenerates and evolves into an even more terrifying second form. Inosuke is nearly strangled to death before Giyu Tomioka arrives in time to finish the battle instantly. Judging Inosuke too injured to continue, Giyu restrains him to prevent further harm.

Meanwhile, Tanjiro confronts the Spider Sister and Spider Brother. He quickly realizes that the “bond” the brother speaks of is one rooted in fear and domination, not true family love. Overpowered in the fight and nearly killed by razor-sharp threads, Tanjiro is saved at the last moment by Nezuko, who reveals the genuine bond between them. This display even tempts the Spider Brother—whose true identity is revealed as Rui, Lower Rank Five of the Twelve Kizuki—to claim Nezuko for himself. Though Tanjiro resists fiercely, his strongest Water Breathing techniques cannot cut Rui’s threads. At his most desperate, he recalls his father’s teachings and unleashes Hinokami Kagura (Dance of the Fire God), while Nezuko awakens her own Blood Demon Art, Exploding Blood. Together, the siblings appear to sever Rui’s head, only to learn he had detached it beforehand to survive. Just as Rui prepares to kill them in fury, Giyu arrives and annihilates him with overwhelming skill.

In his dying moments, Rui recalls his human life, filled with guilt and regret toward his parents. He finally understands that the bond he longed for had been distorted. His soul, reunited with his parents in the flames of hell, departs in sorrow yet reconciliation.

As for the Spider Sister, given one final chance by Rui to prove herself, she attempts to kill more demon slayers, even targeting Murata. However, Shinobu intercepts her. Faced with Shinobu’s overwhelming strength, the Sister begs for mercy, but her lies are exposed, and she is ultimately executed by Shinobu’s poison.

In the climax, as Giyu shields Tanjiro and Nezuko, Shinobu accuses him of protecting demons and moves to attack. Meanwhile, Tanjiro flees with Nezuko, only to be confronted by his fellow trainee Kanao Tsuyuri. Just before she can strike, the Corps Headquarters issues an order: capture Tanjiro and Nezuko alive. When Tanjiro regains consciousness, he finds himself before Ubuyashiki and the assembled Hashira, setting the stage for the next arc.

Running 138 minutes, the film intensifies the Natagumo Mountain battle with cinematic scale and dramatic pacing, preserving the anime’s emotional tension while amplifying the resonance of Tanjiro and Nezuko’s bond. This battle represents a turning point in Demon Slayer: Kimetsu no Yaiba, marking Tanjiro’s first direct confrontation with the Twelve Kizuki and exploring the true meaning of familial ties, making it one of the saga’s most iconic episodes.