Koishi is the younger Komeiji, sister to Satori, and like her, also a satori. While Satori found her own ways to accept and cope with both the ups and downsides to her mind-reading ability, Koishi couldn't handle it. One day, through means she doesn't willingly discuss, she completely sealed her Third Eye, and "killed" the reason she felt feared and hated by others - in the process, sealing her own heart and feelings off from the world as well.

While this did work, and other people ceased to find her frightening, this changed her so much, it didn't mean anything to her at all. She became "static" in her new state, and unreceptive to attempts at opening her up again.

When Satori ordered her own pets to play with her sister, and even giving Koishi some to take care of herself, it only had a minimal affect - at times, she seemed almost to respond, and at others, as if she were only going through the motions. Only the encounter with the Heroines stirred her enough to feel interest and commonplace ambition. Not enough to truly open her heart again yet, but enough to stir it, and rouse long-forgotten parts and the first feeling of regret she's had in ages.


Koishi is at heart a lonely girl who mostly just wants to belong and be accepted. Ironically, in the process of doing the one thing she thought would give her this simple happiness, she completely closed herself off from it.

In the world she exists in now, she is utterly alone in a way no one else can truly comprehend. And the worst part is, she doesn't feel it - her obtaining a state of "highest happiness" as Buddhism puts it, gives her a perpetually carefree feeling that prevents her from realizing what she's truly done to herself. Her heart is shut tight even from herself, and buried deep in a sea of false contentedness.

So she wanders the world like a forgotten ghost that can occasionally be seen by others, leaving and returning home when she pleases, unheralded and unannounced, living according to mercurial whims, and doing as she pleases. She maintains worldly connections, but distantly and at arms length, though she still feels them - her pets, her sister, her home, links she still feels and keeps up, but not with the same investment.

Since she's usually cheery, her interactions with others are almost always with this face, regardless of circumstance - this can make her seem disturbing, lacking in tact and/or empathy and sympathy, or peculiarly detached at varying times. But she can also be a bit Mischievous to get sharp reactions and connections, but seldom to the level of a real prankster - she enjoys a good tease, and otherwise prefers to go along with others' jokes, even at her own expense, since embarrassment too is something she doesn't feel strongly from such things.


After Gensokyo's access to the greater Multiverse, Koishi had a whole larger expanse to explore. Satori had even more trouble keeping in contact with her sister now, and Koishi would be spotted all across the Multiverse in various locations, even inexplicably showing up in places she doesn't belong. Her inherent ability to disguise herself from the majority of people through her manipulation of the subconscious being very useful in evading hostile forces all across the Multiverse, rarely experiencing conflict...and rarely engaging in it. In most scenarios, if she is thrust into conflict, she often chooses to leave instead of stick around and risk herself, even despite her power...it's often not worth the time and risk...


Koishi possesses the power to Read and Manipulate the subconscious.

As a practical matter, Reading it means she can see the base instincts and impulses of others, but unlike Satori's ability, not words, thoughts and details, feelings, or desires - an excellent ability for protecting herself, and a near-useless one for understanding another creature's heart and needs, or communicating with someone who can't otherwise (like animals.)

Her ability to Manipulate it, however, is truly frightening. At its heart, this allows her to subtly play on others' capacity to Perceive and Recognize - without both, from another person's perspective, a thing simply doesn't exist on any level. Koishi mainly makes use of this to an extreme degree, to maintain a state of faux-Mu/Nirvana - a practical death of the "self". If she doesn't make her presence known to be acknowledged, both she, and any actions she commits, won't be recognized by others.

This gives her an invisibility that is more than perfect, allowing her to wander around unseen, unheard, and utterly unnoticed by all around her. It's not that others can't see her, but they literally can't perceive her or her actions' existence until she calls attention to herself to be recognized. Explanations for otherwise unexplainable phenomenon, are shifted onto the user's subconscious to fill in the gap of recognition.

Things she does that others could notice, won't be seen as the work of "some sneaky ninja person hiding around here," but instead shifted subconsciously to whatever other reasons the person might attribute them to - for example, she can eat another's food out from under them, and they will instead believe another in the room did it, they did it themselves before they knew it, etc.

Furthermore, even when recoginized, no creature save perhaps the Yama, can actually sense her as being "there" - you can see her, she's talking to you, she can even be touched, but has no "presence" or sense of self to be felt at all. Even her sister can't perceive her until she makes herself known, or detect/read her thoughts when she does.