[quote=@Scarifar]
Huh, I don't remember Leander ever giving Vincent her name. Must be some human memory mistake somewhere.
[/quote]

Last time i checked he didn't 

page 10 Tsukiko tells vincent her name herself

[hider=here]"Who might you be if you're asking?" Vincent asked looking at her dress. Tsukiko had a hard time finding the words to answer Vincent. He struck her suspicious side and made her somewhat aggressive. She continued to look at him like that as she boldly said only her name. "Tsukiko. Tsukiko Ikushirou." Keeping her introduction with him as blunt as possible as she stared him down with her icy cold gaze. When she was about to say something else to him from what she recalled earlier Ben approached her which drew her attention completely away from Vincent.[/hider]

I like to keep track of things  like this.