Getsuyuu Syndrome (月幽病 Getsuyuubyou, known as Luna Sedata Syndrome in the fanmade translation) is a disease featured in Fatal Frame IV: Mask of the Lunar Eclipse. The disease is featured prominently in the game, and is the driving force behind the island's mysterious deaths and a facet of the islanders' culture.
The Luna Sedata Syndrome is a condition specific to the Rougetsu Island, the disease is incommunicable and does not spread further. It shows symptoms such as memory loss, sleepwalking and "Dancing as if possessed" as the disease advances. The syndrome looks somewhat related to the Moon too, because depending on the phase of the moon, the patients' behavior would change.
When the moon is full, the patient would be calm, but often seek windows or rooftops to be exposed to the moonlight, they say that they feel like they recollect the memories they have lost while bathing in moonlight.
And when there is a lunar eclipse, their conditions worsen. They lose themselves even more, sleepwalk and sometimes become delirious.
The Luna Sedata Syndrome is also related to the failed Kagura Dance/Ritual that caused the happenings of Fatal Frame IV.
There are four stages in the Luna Sedata Syndrome:
Budding is the first stage of the Luna Sedata Syndrome. The patients in this phase tend to be afraid of mirrors, water, or anything that can show their reflection. It is believed that they do so because they cannot recognize their faces, as if the reflection was showing someone else's face.
In the second stage, victims of Luna Sedata Syndrome begin to lose their sanity. It starts with their increased paranoia and confusion about what's happening around them. They may also begin to start hearing voices or noises that no one else can hear.
In the third stage, when a patient sees the face of a patient in a more severe condition, the symptoms get transferred. This is called the "Resonance". For example: If a patient is "budding"and the patient sees another patient who is "blooming", the patient who is "budding" will start "blooming".
It might be the contagious form of the Luna Sedata Sydrome.
Blooming is the fourth and final stage of Luna Sedata Syndrome and it is somewhat connected to the failed Kagura
Ritual. Patients in this state would see their face blurred when they look at themselves. They are the only ones who can see their faces looking this way. Also, when the person who "Bloomed" will be killed, their ghost would have their faces blurred.
Ruka Minazuki - survival confirmed in both endings
Misaki Asou - 1st ending: unknown fate - 2nd ending: survival confirmed
Died in surgery
- The original name, Getsuyuubyou can be translated as "tranquil moon disease" or "secluded moon disease". Although no specific translation is pointed out, the name may refer to how patients enter a state of tranquility while viewing the moon. It might also refer to the disease's relation to lunar eclipses.
- Luna Sedata Syndrome is likely a fictional combination of the words "luna" and "sedate". These, in turn, are derived from the Latin words for moon (lūna) and calm/tranquil.