A simple name for such a simple person. Keiji was typically written with the characters "stained(blackened) tree". Quite a common name, despite it's falloff in popularity into the more modern of eras. Even with the proposed "fall off", it was still a typical name. One might be able to consider this name too "typical" for the apparition before Kokoro; the visage of a person whom should not exist. 

"Keiji, you said you name was? My name is Kokoro; Kokoro Fujiwara. A pleasure to make your acquaintance."

A single word brought forth the attention of a "darker", though at the same time "lighter" sides of Kokoro's personality. A duality off nature, as it were. An inconsiquental construct of desire and longing which had been the forefront of her many choices within life. A construct that would cause both death and rejoice. An evil plague of the world, yet the greatest of all elixirs. 

"I need power," Kokoro simply said to the other. To obtain power was to gain status, and that would bring forth the ideology of Kokoro to another stage, skipping passed many of the former means to such. If this man was telling the truth, she would have advanced in her goals. Justice was a construct held only by the perception of the victors, and to become the victor through power was a means to an end. Justification for actions leading up to a desired point. 

"But what is the cost of such?" 

Power was not something given to others based on such an exchange. Power was something given to others with expectations of the future. One might expect such to progress their own status through knighting and providing others with the necessary supplies to expand influence; standard ponzi scheme. What was the desire of the other before Kokoro? Did he wish to proclaim interest in herself due to an investment construct, or did he simply have no one else to turn to? 

"Maybe you should tell me what you are, I know you cannot be human. What exactly are you? An angel? Devil?" 

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
A comet.
A visage.
Matter. 
A construct. 
A concept. 

A meteor had taken aim at a particular individual. One "Yamato Shirou" 
As if designed to target the individual, to end the other under it's great mass. One might expect that such was the end of this person; a lost individual at the wrong place at the wrong time. Simply put, the presence of "himself" at "point of contact" was a mistake of the greatest calibre. 

Despite this, the existence known as "Yamato Shirou" had not ended. Before the other was a radiant bright that consumed most of his vision. Evidence of a "crater " existed not. Simply, the "falling object" existed not in the vision of "Yamato Shirou", replaced simply by a presence of someone that seemed to belong in this place, yet not belong at the same time. A construct of the highest existence, but one without basis.

"She" spoke to him. 

"Boy, what is it that you desire?" 

A simple test to the person before her.