I've had this idea in my head for a while since Akane and 6 both like to draw and are rather timid/shy... so here's the idea.
Akane and 6 were once good friends, lovers or not, I guess you can decide? But they drew together and showed each other their art, and also let 6 try on some of her robes... but the connection doesn't last forever, or at least, has some bumps in the roads after 6's death.