Koyuki Azumaya

Out of all of the human characters, she has probably one of the more altered personalities.

History of Characterization
Originally, when RabidSonicFan was writing, her personality was moreso based on the interpretation that was in the script for ADV's version of Episode 13; having her just blatantly state that she was a ninja (as well as a stalker). When Mont rewrote the episode, she became much more random (big shocker), constantly trying to impress Natsumi. Though when she's around Dororo, she has more straight dialogue (though the two barely know each other), making it even more random for her to say, especially seeing as Dororo's dialogue was altered, changing the entire context. Thusly, Koyuki seems to be a random girl who came into Dororo's home out of nowhere and won't leave him alone.

Relationships
Dororo - Koyuki ended up stowing away in Dororo's house and he let her stay, due to having somewhat of a lust for her. Because of this, they're seen a lot together and Koyuki is very friendly to him, despite Dororo knowing next-to-nothing about her.

Natsumi - As usual, Natsumi and Koyuki are very good friends. Also as usual, Koyuki has an attraction to Natsumi (though in one episode, it's implied that they have a sexual relationship).