Forbidden Siren Wiki








  • Mana Religion
  • Hisako Yao
  • Shibito


Alive (from eternal time loop)


  • Create and travel through alternate dimensions
  • Able to curse people
  • Can create red water
  • Sightjack


  • Inferno
  • The Nest

Datatsushi (堕辰子) is an extraterrestrial creature in Forbidden Siren, unintentionally setting in motion the game's events, acting as the major influence in the game's storyline.

Crash-landing on planet Earth, he was killed when the people of Hanuda suffered a famine and ate him in the belief that he is a gift from the Gods. In his death, he cursed Hisako Yao, who would then spent countless centuries trying to resurrect him, and erected the Mana religion in his honor.


Datatsushi appears in Hanuda in 684 as a lengthy, albino worm creature, with a slicked appearance to its flesh.

It has 3 pairs of short arms and a pair of legs almost in a state of atrophy, it also has 2 pairs of feeble wings, its head hosts a large mouth and small indentations which appear to be eyes. The lower part of its body can be opened in what seems a second mouth.

Later on in the game, its spiritual form was summoned, which appears similar to its corporeal appearance, save for the fact that its lower portion has sprouted tendrils, and its flesh has become frayed slightly and hanged off its arms, which have also lengthened. It also appears covered in flickering white flame, possibly due to the fact that it is incomplete.

Datatsushi as seen in the nest

Datatsushi as seen in Inferno

Once Hisako Yao offered her own life to Datatsushi in the Inferno, Datatsushi takes on a new form that strongly resembles his description in Hanuda legend: It had 3 insect-like abdomens, with an adjoining thorax and wings. The top half of its body resembles a fish with insect eyes and antennae, and it also has a proboscis.


Datatsushi arrives in Hanuda in 684 AD, when it fell from a comet that passes the Earth every 333 years. It lands in Hanuda on a rock formation (the Mana Stone) that happens to be in the shape of a Mana Cross. There it lays dormant until villagers happen upon it, and due to extreme starvation, devour it, being mistaken for a fish since it was in a helpless, maggot-like immature state at that time.

In its last breath, it curses the starving villagers, killing everyone but a young pregnant Hisako. She is immediately rendered immortal, under Datatsushi's influence, and sought to forever repent for her sins by summoning Datatsushi back to life in the future.

Datatsushi at the feet of the Mana stone, being eaten alive. (684)

The immature form of Datatsushi.

Hisako Yao eating from Datatsushi

Item 49 - Fish from the sky (Part 1)

Datatsushi screaming and killing everyone except a pregnant Hisako Yao.

Item 49 - Fish from the sky (Part 2)

Hisako then creates the Mana (真名 True name) religion and starts adoring that god, as time passes, she poses as the maid of the Kajiro family, her descendants under the name of Sumiko, and eventually forgot her intent to ensure Datatsushi's return.

Time later, in 1976 and still unaware of her purpose; interrupts the ritual and helps the Miyako of that year and his boyfriend Takafumi Shimura (Akira Shimura's son) run away. resulting in a part of the town being buried in a landslide, (mostly the Miyata clinic disappears, pulled into another dimension).  

In 2003, another ritual is used, this time with another descendant named Miyako Kajiro. However, Miyako smashed Datatsushi's head moments before the ritual was conducted, also Kyoya Suda, who is visiting the town, accidentally interrupted the ritual, all this caused the ritual to fail as well. Like before, the 2003 version of the town is sent into an alternate reality. 

The Miyako of 1976 in the basement of the Miyata clinic

Miyako smashing Datatsushi's head before the ritual (2003)

The ritual of 2003

Item 83; diary of the "maid"

In the alternate reality, the water has been replaced by a similar red substance, which allows people to turn into Shibito. There is nothing beyond the island, as a red ocean consumes anything past it, ensuring that no one can leave. The Shibito are loyal to Datatsushi, and whenever his scream, the siren, is heard, they bathed in the red water so that they can evolve and become closer to their god. The red water also allows the Shibito to sightjack each other, due to Datatsushi's insect traits that ends up creating a hive mind between him and his followers. 

Hisako, having remembered what she is supposed to do, found a head washed up along the shore of the town. She sees a white-haired version of herself, smiling in satisfaction. The head is actually that of Datatsushi, sent from the future. With this head, Hisako can use it as the template from which Datatsushi can rise from when Miyako is used as part of the ritual.

Hisako Yao receives the head of Datatsushi in Harayadori (Day 2; 6:44).

Sky 2.jpg

Kyoya and Miyako watch the lights in the sky in Janokubi (Day 2; 7:03)

Item 63; showing the arrival of god

Eventually, Hisako Yao is able to capture Miyako and manages to pull off a successful ritual, resulting in Datatsushi resurrected. Unfortunately, Datatsushi's state is an incorporeal ghost-like being, as unexpectedly, Miyako sent some of her blood in Kyoya, whose blood has also transfered into Shiro Miyata. Datatsushi becomes unhinged, rampaging across the Nest, where the deity is supposed to be housed. During this rampage, he sends Kyoya, Kei Makino and Tamon Takeuchi down further to the bottom of the Nest. He interrupts Tamon and Yoriko's reunion, but sunlight leaks through and burns his ghostly body. Using his dimension-bending abilities, he is able to send himself in Inferno, which houses the comet he arrived to Earth in.

Hisako preparing the sacrfice of Miyako (Day 2; 19:02)

Datatsushi emerges from the flames of Miyako's dead body (Day 3; 00:00)

Datatshushi after it's resurection

Hisako and Jun Kajiro arrive to the Inferno tending to her master. Now in a small, sickened, physical body, he is helpless when Kyoya Suda enters the realm in order to finish off the alien and end the nightmare over Hanuda. Jun Kajiro, who is then a Shibito, faces off against Kyoya to protect his leader. During this, the Uryen is activated through Miyako's blood, and is used to kill Jun. Hisako, in a last bid, offers her strength to Datatsushi so that he can defend himself. The offer works, restoring the god to full strength. Despite this, Kyoya uses the Uryen to burn Datatsushi, and, armed with Jun's family blade the Homuranagi, decapitating him.

Hisako and Datatsushi in Inferno, before Datatsushi recovers. (Day 3; 23:03)

Datatsushi's inner body, during the fight against Kyoya

Kyoya about to decapitate Datatsushi

Datatsushi's head rolls towards Hisako, who then ages to an advanced age with the death of her god ending the curse, and she falls into a vortex in time and space. However, this is not the end of Datatsushi and his faithful servant. The old Hisako, Datatsushi and a box containing the head float down a river and were sighted by the people of Hanuda in the past, leading to a myth involving them. Further along time, the white-haired Hisako appears to her younger self and gives her Datatsushi's head, thus allowing him to be resurrected in the first place, creating a time loop in which Datatsushi's past and future are eternally tied.

Datatsushi burned by the Uryen

Hisako suddenly turns old

Hisako, with Datatsushi's head on her arms, fall intro the ground.

Etymology of the Name[]

There might be 2 possibilities for the origin of Datatsushi's name (堕辰子).

Option 1: Sea horse pun[]

One might be a pun for "Sea-horse"; (Otoshigo 落とし子); but with the first parts changed:

  • 堕 = Due to the graphical resemblance with 落
  • 辰 = Due to the resemblance of (toshi · とし) with (toki · とき), a kun-reading of 辰; and then changed its Kun-reading to (tatsu · たつ) The character 辰 might have been chosen due to the symbolism it gets if combined with 子; then its second Kun-reading was chosen so its connection with (toshi) it wouldn't be too obvious.
  • 子 = The character remains the same, but its reading its changed to (shi · し)

Option 2: Mystic origin[]

Following the first option, the choice of the characters lead to the following meanings:

  • 堕 Data = (verb) To fall
  • 辰子 Tsu·shi = (noun), refers to the 5th and 1st Earthly branches; an ancient counting system from the Shang dynasty in China (1766-1122) and used thoroughly in East Asia until the introduction of the western systems.

堕辰子 might refer for both:

  • Coordinates = Where Datatsushi was originally found (辰 120º, 子 0º north).
  • Time = When Datatsushi fell on earth (辰 3rd month / 7am to 9 am, 子 11th month; 11pm to 1am)

Option 3: Straigtforward description[]

Another option is that the name might simply be a description of the creature, a 'degenerated' or 'corrupt' dragon.

  • 堕 da = Fallen / Degenerated. (堕する dasuru = verb. To degenerate).
  • 辰 tatsu = Dragon (子 shi might be a suffix indicating a young animal or an offshoot).

Seahorse (落とし子)

The earthly branches (十二支)


  • Curses Hisako Yao, who becomes a follower of his; resurrects him; gives him strength in Inferno; makes sure his existence is kept in a loop
  • The 1976 and 2003 Miyako Kajiros involved with rituals used to resurrect him
  • Jun Kajiro protects him in Inferno
  • Resurrection witnesses by Kyoya Suda; killed by him in Inferno
  • Kei Makino follower of Mana religion; witnesses his rebirth
  • Tamon Takeuchi knew of resurrection ritual; unable to stop his rebirth and is sent down into the Nest's lower levels by Datatsushi; almost attacked by the god
  • Yoriko Anno witnesses resurrection; nearly killed by him


  • Datatsushi's head actually resembles the head of a Dogū.
  • There are multiple archive items that say that Hanuda existed since the Jōmon period, maybe that's a hint that the Jomon Dogu and the Uryen are actually based on that god as a means of protection.

Datatsushi's head, as found by Hisako

Item 94; portraying a Dogu head

Dogū Dolls

Item 81.jpg
Item 81 (2).jpg

The Uryen

  • Datatsushi's return is somehow similar to the expected return of Jesus Christ to earth; actually, item 55 represents a being (The Kiruden; 木る伝) strangely similar to the traditional representation of the 4 apostoles.
  • Only the blood of the descendants of Hisako Yao (those with psychic powers) can resurrect Datatsushi; maybe the blood of the Kajiro's is somehow the blood of Datatsushi, similar to the blood of Christ.

Item 55 - The Kiruden

Item 55 (Part 2)

Item 20; the souls of those who touch the red water shall return to their original body.

Item 31 - Bathing in water

Item 31 (Part 2)

Shibito's bathing

The sky as seen by the Shibito

  • There are multiple references about Tsushinoko in the archive items and many cutscenes regarding creatures resembling Tsushinoko, which may be related to Datatsushi or maybe larva-forms of his kind.

Tsushinoko in the Tabori's house bathtub (Day 2; 1:11)

Item 64; Tsushinoko hunt

Tsushinoko found

  • Datatsushi's entire role in filled in by Kaiko in Siren: Blood Curse. With the exception of a name change and different appearance, Kaiko serves as that game's version of the character with no traits from other characters in the original game, unlike the other characters in Blood Curse.
  • Datatsushi (and by extension, Kaiko in the remake) is unrelated to Mother and Otoshigo, despite all three bearing the following similarities:
    • Being able to create alternate realities (Mother)
    • Involved with shibito (Otoshigo)
    • Screams resembling a wailing siren (Mother)
  • Ironically, while Datatsushi is seen by the Mana religion, specifically Hisako, as a god, Mother and Otoshigo are beings that are closer to resembling a deity than himself, as they were made from the darkness left over when Annuko (God) created light and can only be killed by being impaled by his remains. 
  • Datatsushi is the only otherworldly main antagonist who has a movie stage that is as the very start of a game's Link Navigator, as well as the only main antagonist in general to have an unlockable scene.
  • Datatsushi's movie stage is glimpsed at by Miyako in her movie where she is being prepared for the ritual in Day 2. In it, she sees visions of the villagers in 684AD eating Datatsushi.
  • Datatsushi's movie stage serves as the basis for one of the traditions in the Siren franchise; additional movies that are unlocked after the player collects all 100 Archives. Yoriko Anno also has a movie stage which is unlocked through the collection of Archives. 
  • Datatsushi may be inspired by Gozu, the Japanese urban legend that tells of a story so horrific and terrible that those who read or hear it will die of fright. The summary of the story itself is said to tell of a village ravaged by famine. One day, a strange creature with the head of a cow and the body of a man wanders into the village, and is torn apart and devoured by the villagers. Afterwards, the village becomes cursed.