Youkai (妖怪, "mystic apparition" or "mysterious calamity") is a term used to refer to Japanese folk creatures and ghosts, or to supernatural beings in general. Because there are thousands of stories of magical beings around the world, the different types of youkai are endless.
The term youkai is sometimes used interchangeably with obake (お化け, roughly "one that takes on a form"), meaning things which have undergone some kind of supernatural change, beings with shapeshifting powers, or phantoms and ghosts. It is a common Japanese belief that after a certain amount of time, ordinary objects and animals gain life and personality, becoming a kind of youkai. In some cases even a normal human can become a youkai under the right conditions or vice versa.
Youkai in Len'en
Youkai in Mugenri have varying locations. While some live within the dens or just out in the wilderness (such as Shou Amanomori), they are perfectly capable of residing in cities like Devanagara as well. It's rather uncommon (although not impossible) for youkai to mature after coming into existence.
The following is a list of youkai that have appeared in the Len'en Project, in order of appearance:
Faries (妖精 or よーせい) are small, humanoid creatures that can be found roaming anywhere in Mugenri. They are the stage enemies most commonly found throughout the Len'en Project. The way they shoot danmaku all depends on what difficulty the player chooses and what stage they appear in. JynX has stated that information about them is currently a "secret".
Shikigami (式神) are godlike spirits that provide different services for an onmyouji master, some shikigami were originally youkai themself even prior to entering a contract with their master.
Some youkai are based on or manifestations of various natural phenomena:
Certain youkai are based on various living beings, although it is unsure whether they are born youkai, or transformed from animal to youkai. They are capable of transforming between animal and humanoid forms.
- Sea Slug Youkai: Shou Amanomori
- Skylark Youkai: Hibaru Kokutenshi
- Slug Youkai: Kujiru Kesa
- Penguin Youkai: Medias Moritake
The orochi (大蛇 lit. "Giant Snake") are a race of snake-like youkai who transformed out of the various body parts of the dismembered Adagumo clan leader.
The gashadokuro (がしゃどくろ) is a large skeleton youkai born from a massive gathering of skeletons of those who died in war and didn't receive a proper burial, animated by their desire for vengeance.
In the Len'en Project, the only known gashadokuro is Sese Kitsugai. Unlike gashadokuro of real-life lore, Sese was apparently once the animated skeleton of a single human, but has somehow lost much of their bones and thus are thus far weaker than gashadokuro are traditionally said to be. They are capable of temporarily strengthening themself by absorbing souls or other people's bones.
Ghosts (幽霊 yūrei, lit. "ethereal soul/spirit") is a general term used to refer to incorporeal entities that are most typically tied to nature, a person's soul, or the afterlife.
Oni (鬼 oni) are youkai in Japanese legends known for their immense strength, and are commonly portrayed as having horns on their head and carrying large iron clubs. Similar to ogres or trolls in western folklore.
A tsukumogami (付喪神) is a type of youkai produced from a tool or object inhabited by a god or a spirit.
- Youkai Haniwa (化け埴輪 Bake Haniwa): Sukune Katano is a youkai based on Haniwa (埴輪, lit. "circle of clay"[a]), terracotta clay figures which were made for ritual use and buried with the dead as funerary objects during the Kofun period in Japan. It is unclear whether Sukune was born of a haniwa statue or is simply a youkai manifestation of the concept. It is said that the haniwa made by Sukune are perfect vessels for divine spirits (神霊 Shinrei).
- The Harujion (ハルジオン): A youkai philadelphia fleabane that occasionally blooms within Mugenri.
- Tsugumi Umatachi: Tsugumi's race has been listed as both an "oseibo jockey" and a "harvest festival jockey", but it is unclear what type of youkai they are.
Characters under this Bestiary
- Adagumo no Saragimaru (Orochi)
- Adagumo no Yaorochi (Orochi)
- Harujion (Youkai daisy flower)
- Hibaru Kokutenshi (Skylark youkai)
- Jinbei (Shikigami)
- Jun Amanomiya (Rain youkai)
- Kujiru Kesa (Slug youkai; Shikigami)
- Lumen Celeritas (Sunlight youkai)
- Medias Moritake (Penguin youkai)
- Mitsumo (Tsukumogami)
- Sese Kitsugai (Gashadokuro)
- Shion (Chimera soul)
- Shou Amanomori (Sea Slug youkai)
- Sukune Katano (Haniwa youkai)
- Taira no Chouki (Dead spirit)
- Taira no Fumikado (Homuncular Oni, formerly human)
- Tsugumi Umatachi (Oseibo jockey)
- Despite sharing many similarities with animal youkai, Kaisen Azuma insists that they are referred to as a sacred animal (霊獣 Reijū) instead of a youkai.
- Touhou Wiki's entry for Youkai
- Wikipedia's entry for youkai
- Yokai.com, a site listing and describing a large number of youkai.
- hyakumonogatari.com another similar site.
- A reference to how haniwa were arranged in a circle above the tomb.
- JynX's Twitter: "The youkai of Mugenri can have a place of residence just like humans, there are also some that live in dens or out in the wild. I'll talk about where youkai live in detail at a later point, as for those four's [Yaorochi, Saragimaru, Jun and Shou's] lives, I'll leave it up to your imagination~."
- Brilliant Pagoda or Haze Castle: Preschool Team's Neutral Scenario - Jun Amanomiya
- Len'en Wiki:Interview with JynX (2017): Miscellaneous, Question 70
- Interview with JynX (2021): Sese Kitsugai, Q.229