Top 10 Supernatural Mystery Anime Like The Detective Is Already Dead You Need To Watch

Some anime grab my attention because of their action scenes, while others keep me watching because I need to know what happens next. The Detective Is Already Dead (Tanmoshi) manages to do both, and that combination is exactly what makes it so memorable. One moment, Kimihiko Kimizuka and Siesta are trading sarcastic remarks, and the next, the story throws them into a dangerous conspiracy involving supernatural enemies, strange technologies, and secrets that are much bigger than either character initially realizes.

What I personally enjoy most about Tanmoshi is the contrast between its playful dialogue and underlying sadness. Siesta isn’t simply a brilliant detective who solves impossible cases. Her relationship with Kimihiko gives the story an emotional weight that remains even when she isn’t physically present. Their partnership, the mystery surrounding her legacy, and the feeling that something terrible is always lurking in the background make the series more interesting than a conventional detective anime.

If you’ve finished Tanmoshi and want something with a similar mix of supernatural mysteries, clever protagonists, unexpected twists, and emotional storytelling, there are plenty of excellent options. Some lean more heavily into detective work, while others focus on paranormal phenomena, psychological puzzles, or secret organizations.

Here are 10 supernatural mystery anime like The Detective Is Already Dead that deserve a place on your watchlist.

1. In/Spectre (Kyokou Suiri)

Best for: Supernatural investigations, clever dialogue, and an unusual detective partnership.

If I had to recommend one series to someone who particularly enjoyed the investigative side of Tanmoshi, In/Spectre would be near the top of my list.

The story follows Kotoko Iwanaga, a young woman who becomes the God of Wisdom for supernatural creatures after sacrificing an eye and a leg. She mediates disputes between humans and yokai, using intelligence and carefully constructed arguments to prevent supernatural conflicts from spiraling out of control. Her partner, Kurou Sakuragawa, possesses unusual abilities that make him exceptionally difficult to kill.

What makes this anime stand out is its approach to solving mysteries. Kotoko doesn’t always search for the simplest explanation or even the objectively correct answer. Sometimes, she constructs a convincing story that changes how people understand a supernatural event.

That distinction makes the investigations surprisingly entertaining. Instead of relying entirely on action, the series allows conversations, competing theories, and psychological manipulation to drive the plot.

Fans of Siesta’s confidence and Kimihiko’s dry reactions should appreciate the dynamic between Kotoko and Kurou. Their relationship has a different personality, but the combination of a sharp-tongued female lead, an unusually capable male partner, and paranormal mysteries feels familiar.

2. Killed Again, Mr. Detective? (Mattaku Saikin no Tantei to Kitara)

Best for: Detective fiction with supernatural complications and dark humor.

This recommendation is especially appealing if you want a story that plays with the traditional detective formula rather than simply repeating it.

The protagonist, Sakuya Oitsuki, is a high school detective who follows in the footsteps of his legendary father. Unfortunately, his profession comes with an extraordinary problem: he repeatedly finds himself in situations where he is killed, only to return to life.

His work frequently takes him into bizarre and dangerous cases, and his relationship with his assistant, Lilitea, adds another layer to the investigation-heavy storytelling.

The premise creates an interesting reversal. In many detective anime, the investigator stands outside the crime and reconstructs what happened. Here, Sakuya’s own experiences as a victim become part of the investigative process.

That is one reason Tanmoshi fans might enjoy it. Kimihiko’s life changes because of his connection to Siesta, while Sakuya’s unusual circumstances make danger an almost unavoidable part of his profession.

The tone is not identical to Tanmoshi, and viewers should expect a different balance of comedy and mystery. Still, if you like detectives who cannot seem to escape trouble, this is a fun choice.

3. Undead Girl Murder Farce

Best for: Gothic mysteries, supernatural creatures, and brilliant investigators.

Undead Girl Murder Farce is one of my strongest recommendations for anyone who wants detective work mixed with stylish supernatural action.

Set in an alternate nineteenth-century Europe, the anime follows Aya Rindo, an immortal woman whose severed head is carried inside a birdcage. Alongside Tsugaru Shinuchi, a half-demon fighter, and the loyal Shizuku Hasei, she travels across Europe solving cases involving vampires, werewolves, and other extraordinary beings.

Aya’s intelligence is the main attraction. She approaches complicated incidents with a level of confidence that makes even seemingly impossible crimes feel solvable. Tsugaru provides a more physical approach to danger, creating a satisfying contrast between deduction and combat.

The series also knows how to make its mysteries visually compelling. Its historical setting, theatrical character designs, and supernatural atmosphere give every investigation a distinctive identity.

There is an obvious thematic connection to Tanmoshi, particularly in the idea of a brilliant female detective whose unusual physical circumstances become central to the story. However, Undead Girl Murder Farce feels more like a traditional mystery adventure with elaborate supernatural worldbuilding.

If you want clever deductions, memorable character interactions, and action that actually complements the investigation, don’t skip this one.

4. Rascal Does Not Dream of Bunny Girl Senpai

Best for: Emotional supernatural mysteries and witty character interactions.

Despite its unusual title, Rascal Does Not Dream of Bunny Girl Senpai is much more than a high school romance.

The story follows Sakuta Azusagawa, who encounters mysterious phenomena known as Puberty Syndrome. These supernatural occurrences are connected to emotional distress and can produce effects that appear to defy reality. His first major encounter involves Mai Sakurajima, a famous actress whose existence seems to be disappearing from other people’s awareness.

What follows is a collection of interconnected mysteries that explore loneliness, identity, anxiety, relationships, and the pressure of growing up.

The biggest reason I recommend this anime to Tanmoshi fans is its dialogue. Sakuta and Mai have a wonderfully dry, sarcastic way of speaking to each other. Their conversations often reveal more about their personalities than lengthy explanations ever could.

Like Kimihiko and Siesta, they have a relationship that develops through humor, trust, and moments of genuine vulnerability.

The mysteries are usually rooted in the characters’ emotional struggles rather than secret organizations or supernatural battles. That makes the series less action-oriented than Tanmoshi, but arguably more intimate.

If your favorite parts of Tanmoshi were the bittersweet moments between its leads, this anime could easily become your next obsession.

5. Bungo Stray Dogs

Best for: Supernatural abilities, secret organizations, and high-stakes conspiracies.

If you enjoyed the dangerous organizations and large-scale conflicts in The Detective Is Already Dead, Bungo Stray Dogs is an excellent next step.

The story begins with Atsushi Nakajima, an orphan who encounters Osamu Dazai and becomes involved with the Armed Detective Agency. Its members possess supernatural abilities, and their investigations frequently bring them into conflict with the Port Mafia and other powerful groups.

Although the series contains plenty of detective work, its greatest strength is the way individual cases connect to much larger conspiracies. Characters who initially appear to be straightforward allies or enemies often have complicated motivations, and their supernatural abilities make confrontations unpredictable.

Ranpo Edogawa is particularly enjoyable for viewers who love the classic genius detective archetype. His confidence and extraordinary powers of deduction can make solving a case look almost effortless, although the surrounding circumstances are rarely simple.

Compared with Tanmoshi, Bungo Stray Dogs has a larger ensemble cast and places more emphasis on factional conflict. However, the combination of mysteries, unusual powers, sharp dialogue, and emotionally complicated characters makes it a natural recommendation.

It’s also a great choice if you prefer anime where the world expands considerably as the story progresses.

6. The Case Study of Vanitas (Vanitas no Carte)

Best for: Gothic fantasy, vampire mysteries, and morally complicated characters.

Set in an alternate nineteenth-century Paris, The Case Study of Vanitas follows Noé Archiviste, a vampire searching for a legendary grimoire called the Book of Vanitas.

His journey brings him into contact with Vanitas, a human who claims to use the book’s powers to cure vampires afflicted by a mysterious condition that can turn them into dangerous creatures.

Their uneasy partnership becomes the foundation for a series of investigations involving supernatural illnesses, hidden motives, and secrets surrounding the vampire world.

What I love about this premise is that the mystery isn’t limited to identifying a culprit. The characters also have to figure out why these events are happening and whether the people involved can actually be trusted.

Vanitas himself is a fascinating protagonist. He’s theatrical, unpredictable, occasionally infuriating, and clearly hiding more than he reveals. His interactions with Noé are entertaining precisely because their personalities and beliefs frequently clash.

The anime also delivers gorgeous backgrounds, expressive animation, and atmospheric action sequences.

If Siesta’s charisma was one of your favorite aspects of Tanmoshi, Vanitas offers a different but equally compelling take on the brilliant, enigmatic lead. Just expect more gothic fantasy and vampire mythology than conventional detective cases.

7. Un-Go

Best for: Philosophical mysteries, political conspiracies, and supernatural deduction.

Un-Go is an underrated option for viewers who prefer their detective stories to explore uncomfortable questions.

The series takes place in a near-future Japan recovering from war. Shinjurou Yuuki is an investigator known as the Defeated Detective because his attempts to uncover the truth often conflict with the explanations society would rather accept.

His partner, Inga, possesses a supernatural ability that forces people to answer a question truthfully under specific circumstances.

This creates an interesting investigative partnership. Shinjurou must gather evidence, interpret behavior, and identify contradictions, while Inga can provide a shortcut to information that would normally remain inaccessible.

However, getting an answer isn’t necessarily the same as understanding a case. Motives, political interests, and the consequences of exposing the truth remain important parts of the story.

That is what makes Un-Go especially interesting for Tanmoshi fans who enjoy mysteries involving hidden technologies and powerful organizations. Both anime explore worlds where the official explanation may not reveal the complete picture.

The atmosphere is more restrained and politically focused than Tanmoshi, but the central question remains compelling: what does it really mean to solve a mystery when the truth itself can be manipulated?

8. Summer Time Rendering

Best for: Time Loops, Survival Horror, and Supernatural Conspiracies.

If you want something more intense, Summer Time Rendering should be high on your list.

Shinpei Ajiro returns to his island hometown following the death of his childhood friend, Ushio. What initially appears to be a tragic accident soon develops into a terrifying mystery involving supernatural entities called Shadows.

These beings can imitate living people, creating an environment where nobody can be trusted completely. After experiencing death himself, Shinpei discovers that he can return to an earlier point in time, giving him opportunities to investigate events and change their outcomes.

The catch is that every loop brings new complications. Information that seems reliable in one timeline may become dangerous in the next, and Shinpei must learn from his mistakes if he wants to survive.

This is one of the strongest recommendations here for viewers who enjoy trying to solve the mystery alongside the protagonist. Small details matter, character behavior can reveal hidden information, and the larger conspiracy gradually becomes more disturbing.

The connection to Tanmoshi lies in its mixture of a beloved female character’s death, supernatural danger, and a protagonist who must confront a threat much larger than himself.

However, Summer Time Rendering is significantly more focused on survival, suspense, and strategic problem-solving. Once the central mystery gets moving, it becomes remarkably difficult to stop watching.

9. Beyond the Boundary (Kyoukai no Kanata)

Best for: Supernatural Action, Emotional Drama, and Hidden Worlds.

Produced by Kyoto Animation, Beyond the Boundary combines supernatural combat with a story about isolation, friendship, and the consequences of being different.

Akihito Kanbara appears to be an ordinary high school student, but he is actually an immortal half-human, half-Youmu being. His life changes when he meets Mirai Kuriyama, a young warrior who can manipulate her own blood into a weapon.

Mirai’s responsibilities involve hunting dangerous supernatural creatures, and her encounter with Akihito draws both characters into a much larger conflict.

The series doesn’t follow a conventional detective structure throughout, but its hidden supernatural world and unfolding mysteries should appeal to Tanmoshi viewers.

I particularly like the contrast between its everyday school scenes and its more serious moments. The characters can be funny and awkward one minute, then face situations that challenge their beliefs and relationships the next.

The animation is another major selling point. The action scenes are fluid and visually striking, while the quieter sequences give the characters room to develop.

Choose this one if you want the emotional side of Tanmoshi alongside supernatural battles, unusual abilities, and a mystery that gradually reveals the stakes behind its characters’ lives.

10. ID: INVADED

Best for: Psychological Thrillers, Mind-Bending Mysteries, and Sci-Fi Detective Work.

Rounding out the list is ID: INVADED, an anime that takes the detective genre in a more experimental direction.

In this science-fiction thriller, investigators use advanced technology to enter artificial environments constructed from the subconscious drives of murderers. These surreal spaces, known as ID Wells, contain clues that can help investigators understand crimes and track down their perpetrators.

The central character is Akihito Narihisago, a former detective whose own traumatic past makes his involvement in these investigations especially complicated.

Rather than presenting conventional crime scenes, the series throws its investigators into abstract worlds governed by strange rules. Solving a case requires interpreting the environment, understanding the killer’s psychology, and recognizing which details matter.

The overarching pursuit of a mysterious serial killer known as John Walker connects individual investigations to a much larger puzzle.

For Tanmoshi fans, the appeal comes from the combination of advanced technology, fragmented information, psychological tension, and a mystery that keeps expanding.

The setting is more science fiction than supernatural fantasy, but the experience of watching characters piece together an increasingly complicated conspiracy feels very familiar.

If you enjoy anime that encourage you to form your own theories and reconsider what you thought you understood, ID: INVADED is well worth your time.

Nagisa Natsunagi and Siesta Consciousness Connection Explained: What to Expect in The Detective Is Already Dead Season 2

Which Anime Should You Watch First?

Not every series on this list captures the same aspect of The Detective Is Already Dead. Some focus on the relationship between two unusual partners, while others emphasize complex investigations or dangerous supernatural forces.

Here’s a quick guide to help you choose:

Final Thoughts: Finding Your Next Tanmoshi-Like Anime

The reason The Detective Is Already Dead leaves such a strong impression isn’t simply that it features a genius detective or supernatural enemies. It’s the way its mysteries connect to the characters themselves. Kimihiko’s relationship with Siesta gives the story an emotional center, making even the most action-heavy moments feel connected to something personal.

That’s why I wouldn’t recommend looking only for anime with detectives. The best alternatives are the ones that combine mystery with compelling character dynamics, whether through paranormal investigations, science-fiction technology, time loops, or supernatural conspiracies.

Personally, I’d start with In/Spectre if you want clever dialogue and a detective partnership, Undead Girl Murder Farce if you prefer elaborate cases and stylish supernatural action, or Summer Time Rendering if you’re looking for a suspenseful mystery that constantly raises the stakes.

For something more emotional, Rascal Does Not Dream of Bunny Girl Senpai is an excellent choice. And if you want a bigger world filled with secret organizations, dangerous abilities, and characters whose motivations aren’t always obvious, Bungo Stray Dogs deserves your attention.

You might not find another series that recreates the exact chemistry between Siesta and Kimihiko. But that’s part of the fun of exploring supernatural mystery anime: each show takes familiar ingredients and combines them in a completely different way.