The Siren is a common link and feature in the Forbidden Siren series. Like the name suggests, it manifests as a sinister howling noise, similar to an air-raid siren. It makes an appearance in all of the games of the series with a similar function.
In Forbidden Siren, the Siren first appears after Kyoya accidentally runs over the police officer. It blares loud enough to disorientate Kyoya and causes him to see flashing visions of an alien nature. It can be assumed that the Siren's sound rends reality to the point that the characters can Sightjack. The Siren then makes repeated appearances in the game, usually at specific points in time. On more than one occasion, the Siren rings out at precisely midnight, but the length at which it continues may vary, as it has been heard at as late as 3pm.
The Siren originates from Datatsushi, a fallen alien creature that arrived in Hanuda via a meteor that periodically passed Earth. The villagers of Hanuda were suffering a drought and ensuing famine. Once they happened upon the large body of Datatsushi, they began to devour it. From the intense pain, the creature screamed and it echoed throughout the heavens, deafening the villagers and cursing a particular one (Hisako Yao) to an eternal life.
It can be assumed that since Datatsushi is not a terrestrial creature, its voice (and therefore, the Siren) has otherwordly effects on Earth.
The Siren disorientates humans to the point that they open their mind to a new way of seeing reality. This coupled with exposure to Red Water transforms them into Shibito. The main characters all display visual pain from the intensity of the loudness.
Forbidden Siren 2Edit
In Forbidden Siren 2, the Siren rings out when Kanae falls to her death after being chased by the Ohta family and their fisherman companions. The sound appears to cause the seas around the island to collapse onto the mainland in the form of a tidal wave, releasing Shiryos all over the island.
The Siren comes from Mother, who uses it in the game three times chronologically to summon two different forms of monsters. The first time it is used, it summons Shiryos from the surrounding seas to invade the island, but since the seas house Otoshigo, it may be assumed that the Siren was simply Mother attacking the islanders directly and the Shiryos invasion was accidental. The second time, Mother summons the Yamirei from underground, allowing them to dominate the island. The third and final time is just before she reaches the top of the pylon and reach the real world.
Like its predecessor, the Siren hurts people with its deafening sound, but its connection with Shibito no longer exists. Instead, the Siren is more symbolic of Mother's rage and it sounds whenever a significant event has occured in her ascension.
Siren Blood CurseEdit
As in Forbidden Siren, the Siren first appears after Howard kills the Shibito police officer. It blares loud enough to disorientate him before he is shot by the revived Shibito. It then frequently sounds whenever night falls, and the times of it sounding are more sporadic than that of the original game.
The Siren originates from Kaiko, an otherworldly being that appeared in Hanuda aeons ago. Due to the events in Hanuda of 2007, Bella Monroe ends up in the village's past when Kaiko appeared and she begins to devour him (as the village is suffering a drought). This act causes Kaiko to scream in pain, cursing Bella, who eventually grows to become Amana.
The Siren sounds different to the first two games' version (which were both identical), but its function remains the same as the original game. However, a significant event is after Kaiko's death, whereupon the Siren sounds again while Sam Monroe wails in despair and falls through a portal. This is significant as the Siren should not sound due to Kaiko's death, which reveals that Kaiko has been sustained by the time loop and the events of Hanuda will repeat forever.