Mika is a gal who is quite knowledgeable and rather interested in bondage to an alarming degree for a girl her age, so she knows the habits and tactics of various villains while only allowing the ones she likes and who will abide by her rules to tie her. It's still a safer alternative than trying to take her by force and risking being caught by her bodyguards. Since she's small, it's best to not use any shibaris on her, but don't hesitate to use tight binds. She's got an adorable face, so don't cover too much of it with her gag. A cleave or OTM is a good choice.