Fujiwara no Mokou

Perhaps due to her long ostracization, Mokou is a loner by nature and prefers not to socialize with either humans or youkai. She accompanies lost people she finds in the Bamboo Forest, considering herself a guide through the Bamboo Forest, and even after being escorted between the Village of Humans and Eientei, she leaves without saying a word. However, to those she is familiar with, she speaks directly and vividly. For example, she was easily agitated and ranted about how annoying Kaguya was. Not much else is known about her, as she doesn't socialize much with anyone.

Her style can be characterized as masculine - she wears a shirt with suspenders and a karusan (a type of hakama usually worn by men) tied at the waist, rather than above the waist as is common for women's hakamas. Although in "The Imperishable Night" she used feminine speech patterns, beginning with "Urban Legend in Limbo" her speech is also typically masculine.

She takes it upon herself to accompany the people in the Bamboo Forest of the lost. Although this allows her to communicate with other people, she still remains very speechless. For example, when asked about her past, she doesn't answer anything other than "I'm just a regular health maniac who runs a yakitori stand" (it's unclear if she actually runs a yakitori stand). However, she seems to enjoy listening to what others have to say. Thus, even if one doesn't go out of one's way, conversation can revitalize her.

Currently, she seems to be very content with her life, contrary to what is commonly thought of as a pessimistic lifestyle. Possessing an ageless, undying body, she and Kaguya Houraisan kill each other every day, and the text of The Imperishable Night even emphasizes this with the line "and she's alive to enjoy it, how splendid!".

Mokou's inability to die allows her body to receive an indefinite amount of punishment. No matter whether she's beheaded, incinerated or has taken any other form of strike, she'll always revive without exception. Mokou will recover within a few day's time if she takes a non-fatal blow. Due to the nature of the Hourai Elixir she drank over 1300 years ago, she's also incapable of contracting any form of disease or illness. This includes the natural process of aging.[1] It is said she can completely recover even if a single hair remained[2], although it seems redundant because those who taste the elixir will recover regardless.

Mokou's immortality, however, doesn't prevent her from being susceptible to fatigue. Even though she is incapable of dying, she still feels pain when injured just as a normal human does. It's said that since she doesn't die, feeling the sting of death when she reaches the brink of oblivion brings her a great deal of pain and fatigue when she immediately revives. For this reason, she can be defeated in spell card matches with danmaku even though she's invincible. It should be noted though, that this fatigue may be completely mental since she needs no sustenance such as food or sleep to stay alive.

Though never clearly described, Mokou appears to have some sort of control over fire. Many of her spell cards symbolize phoenix imagery, though this is most likely an aesthetic choice by Mokou (due to the phoenix being symbolic of immortality) rather than having any real meaning. The fact it took the combined efforts of her, Kaguya, and several rabbits to put out a forest fire in her Bohemian Archive in Japanese Red article implies that while she's capable of starting and increasing fire, she might not necessarily be able to extinguish it.

Mokou was born as a daughter to the Fujiwara family during the Asuka and Nara periods. It's been estimated that it was around 700CE (i.e., currently about 1300 years old). It seems that she was an unwanted child because she wasn't allowed to go out in public.

Around 1300 years ago, Kaguya Houraisan embarrassed Mokou's father – and entire family – by presenting him with an impossible request when he asked for her hand in marriage (as had happened with many other young men). Mokou grew to resent the moon princess, and searched for a way to spite her, but Kaguya disappeared, apparently returning to the moon before Mokou could take revenge.

She finally found a way, by making an attempt to steal the Hourai Elixir for herself that Kaguya left for the Emperor of Japan of that time because it was something very important to Kaguya. She followed a group of soldiers led by a man named Iwakasa in secret, who were going up what is now Mount Fuji. However, it was difficult for her to climb the mountain alone without proper equipment, so she quickly ran out of energy. Iwakasa had realized that she was following them some time prior to this, so once Mokou couldn't move on anymore, he helped her and they continued on, reaching the summit as one group. Once there, Mokou discovered that the group of soldiers planned to fling the jar into the fires of the volcano to destroy it, on orders from the current Emperor of Japan. As they were about to throw it in, the goddess Konohana-Sakuyahime, who calms the eruptions of Mount Fuji, appeared and forbid the group to throw the jar into the volcano because Mount Fuji's volcanic activities would restart should they do so. She explained to them that it was in fact the Hourai Elixir, the elixir of immortality. She gave the command to go to Yatsugatake where her older sister Iwanagahime handles immortality and unchangingness dwelt.

The soldiers tried to light the jar on fire, but Sakuyahime's powers prevented it. What happened after is unclear; Mokou believes that Iwakasa's men were killed by Konohana during their night watch because they tried to take the elixir for themselves as Iwakasa and Mokou slept. As the two got further down, Mokou was finally possessed by the desire for immortality, so she murdered Iwakasa and stole it from him, consuming it and thus became immortal.

After achieving immortality, she had an undying body, but humans who don't grow older aren't able to live as an ordinary humans, so until she drifted to Gensokyo, she moved from place to place, never stopping to dwell in one location. She spent three hundred years in isolation, away from the hateful eyes of people. For three hundred years after that, she would destroy anything that crossed her path, but after that, she spent three hundred years in boredom as the youkai couldn't hold her interest any longer. It's assumed that during these six hundred years she appeared in Gensokyo. It's unknown exactly when Mokou came to Gensokyo, but after nine hundred years total, she found out that Kaguya did not actually return to the moon but continued a life of escape, and that Kaguya also became one with an undying body.

Mokou was ecstatic in discovering someone who was in the same mess she was in. Since then Mokou and Kaguya have mutually killed each other day in, day out for about 300 years. After the incident of Imperishable Night, perhaps due to the influence of Eientei accepting patients who come for medical examinations, she also started creating her own connection with the humans of the Human Village by taking the position of an escort and guiding people through the bamboo forest who want to go to Eientei. She remains very reticent, however.

On Maribel Hearn's trip to the Bamboo Forest of the Lost of several hundred years ago she met a girl who seems to be Mokou.[3] She rescued her from a mouse or rabbit youkai, which then ran away and hid after "a girl entirely on fire" chased the youkai away without a word exchanged between the two. In Perfect Memento in Strict Sense, Hieda no Akyuu speculates that Mokou is a descendant of a hidden group of "youkai-killing ninja". People in general are doubtful of the clan's existence. Akyuu claims that Mokou feigns ignorance when asked about it.

Ageless; existed for over 1300 years

Human

Mokou has red eyes and ankle-length white hair. She wears a light brown shirt that appears as if it's been discolored from fire, and dark red sashinuki hakama that are randomly decorated with paper charms.