[quote=@Lewascan2]
<Snipped quote by Guardian Angel Haruki>

Malcer's got three years on her, so the most likely time for them to have met was either in college or in high school. Either way, the age gap means they likely only knew each-other a year or so at most before Malcer would have to move on due to graduation, and they'd have had to stay in contact online past that. Malcer was probably hosting -or participating in- some form of tabletop RPG in either case that he might have invited her to try out if they hit it off, as it's the way he'd have found it easiest to connect to people back then.
[/quote]

I'm thinking they probably met when Ciel was in late Middle School to Early High School considering the three year gap, and Bartholomew appeared during her college years.

Ciel was up for trying new things before Bartholomew, and realizing that it's easier for him to connect, so she would have been more than happy to try out Tabletop RPG if she had the invitation. After that, she would definitely stay connected with him online, until Bartholomew intervenes.