@Minutoh
You have it backwards and it's slightly weirder than that. They're both satori youkais (yes, a satori named Satori), which is, mind readers with a third eye that is also their heart(mind). Because they read minds (and because they make it really clear they're doing it) satoris are hated among youkai and people alike (animals love them, tho).
Koishi couldn't stand the hate, so she closed her third eye to stop her mind reading. Problem is, that also shut her heart/mind.
Now, this is where it gets hard to explain, and I'm not so sure I understand myself but let's go.
Shutting her mind means now Koishi is running 100% on her "unconscious". In addition, she gained the ability to manipulate other people's unconscious. Finally, in the simplest terms I can find, people can't really notice her unless they interact directly with her, and even then, once their interaction is done they forget about her.
Satori would be one of the few people who can remember her since, you know, they're sisters and she knew her from before the eye shutting.
TL;DR Koishi is the one that gets forgotten, and yes that makes for a lot of potential (and raw) drama.
last edited at Jul 22, 2017 11:57PM