Tatsuya Endo, the mastermind behind Spy x Family, initially envisioned the series as a dark psychological thriller. His early concept explored espionage, deception, and mind games with a more serious tone. However, as he refined his ideas, he shifted toward a mix of action, humor, and heartwarming family dynamics, creating a story that resonated with a broader audience.
Endo’s decision to rework the series stemmed from a desire to balance intensity with lighthearted storytelling. While the spy genre remained central, he introduced comedic elements and wholesome character interactions. This transformation gave birth to the beloved trio of Loid, Yor, and Anya, turning the series into a global sensation rather than a grim, psychological narrative.
From Dark Thriller to Family-Oriented Adventure

Twilight aka Loid Forger | Spy X Family
The original concept for Spy x Family focused heavily on espionage and psychological manipulation. Endo initially crafted a protagonist embroiled in a web of lies and conspiracies, where trust was scarce. This darker premise would have made for an intense, suspenseful experience, contrasting sharply with the comedic and heartwarming moments that define the series today.
As the story evolved, Endo introduced warmth and humor into the narrative. He restructured the dynamics, shifting from an atmosphere of paranoia to a heartfelt tale of an unconventional family. Loid, Yor, and Anya’s relationships became the heart of the story, adding a layer of charm that complemented its action-packed sequences.
A Perfect Blend of Action and Emotion

Spy X Family (Credits: Wit Studio)
Spy x Family strikes a rare balance between thrilling action and emotional depth. Despite the lighthearted tone, the series still explores espionage, secret identities, and moral dilemmas. Endo carefully preserves elements of suspense while making the characters’ interactions endearing and entertaining, ensuring the audience remains engaged.
This approach has allowed the series to appeal to a wide range of fans. The blend of thrilling missions, comedic misunderstandings, and touching family moments has made Spy x Family a standout success. Endo’s decision to steer away from a purely dark narrative ultimately shaped one of the most beloved manga and anime franchises today.

Spy × Family follows master spy Loid Forger (code-named Twilight), who must build a “fake family” to carry out Operation Strix, his mission to get close to a political target. He adopts telepathic child Anya, marries assassin Yor, and even acquires a precognitive dog Bond, all while none of them know each other’s secrets.
Koyoharu Gotouge, the creator of Demon Slayer, originally had a drastically different vision for Tanjiro Kamado. In the earliest drafts of the series, Tanjiro was not the kind-hearted warrior fans know today but was instead written as a villain. This alternate version explored a much darker path, where Tanjiro could have become a formidable antagonist rather than a heroic Demon Slayer.
The original concept leaned heavily into themes of vengeance and despair. Gotouge considered making Tanjiro a character who succumbed to darkness after witnessing his family’s slaughter. Rather than fighting demons to protect humanity, he was initially meant to embrace his rage, possibly even becoming a demon himself. However, as the story evolved, so did Tanjiro’s role.
A Shift from Tragedy to Hope

Demon Slayer
Had the original version been realized, Demon Slayer would have taken on a much more somber tone. A villainous Tanjiro would have drastically altered the series’ emotional core, shifting it from a tale of perseverance to one centered on destruction and revenge. His transformation into a hero instead introduced themes of resilience, kindness, and inner strength, which became defining traits of the story.
Early designs of the demon slayer characters. The show was originally gonna be much darker and have no comedy in it. Story would be about emotionless Tanjiro seeking revenge. by u/SakeTube in DemonSlayerAnime
Gotouge ultimately chose to make Tanjiro a beacon of hope rather than despair. This decision allowed the series to highlight the struggles of those fighting against demons while maintaining an emotional depth that resonated with fans. Tanjiro’s unwavering compassion became the heart of the narrative, giving the story its uplifting and inspirational elements.
The Impact of Tanjiro’s Heroic Path

Tanjiro and Zesuko | Demon Slayer Season 4 (Credits: Ufotable)
By shifting Tanjiro’s role, Demon Slayer became a story about overcoming pain rather than being consumed by it. His journey emphasized themes of empathy, determination, and sacrifice. If he had been written as a villain, the series might have followed a much bleaker trajectory, possibly focusing on his descent into darkness rather than his fight against it.
Tanjiro’s heroic nature has made him one of anime’s most beloved protagonists. His character stands as a testament to the idea that even in the face of immense suffering, one can choose kindness over cruelty. Gotouge’s final decision to make Tanjiro a hero instead of a villain helped shape Demon Slayer into the powerful and emotionally resonant story fans cherish today.