Maya's Links
Maya and Ami are actually extremely close friends, although they like to keep their friendship secretive due to the sensitive nature of Maya's work. Both of them feel that the other is among a very small circle of people they can trust.
While Ami had often seen Maya at various elegant dances and dinners before, the two only really became friends after he caught Maya attempting to murder one of his employers' friends on Christmas Eve. (Great friendship opportunity, amirite?) While most rational people would turn an assassin in, Ami's curiosity was piqued by Maya and the two quickly realized that they were both holding up false 'personas' over their true identities. Ami feels that Maya is one of the only people he can truly be himself around, and vice versa. However, their friendship must be kept a secret as either could easily be used as a bargaining tool for the other if word got out.
Maya has been trying to kill Rosie for like... five years, now? Six? She's not really sure. While Maya's original contract to kill Rosie was called off only a month in due to Rosie's brother Solace making a deal with Maya's employer, she knows that Rosie knows what Maya's face looks like now which is a pretty big risk. However, Maya has bigger fish to fry so her attempts to off Rosie are halfhearted at best.