Hmmm, so the fetish stays in the gene. Which means for fetishes to change from one generation to another, the only way is to have 2 people with different fetishes marry and have a kid. As shown by Tatsu's sister who has a different fetish from her mother while Kotoka and Tatsu have the same fetish as their parents. Does that also mean there was a chance Kotoka's fetish would have been different or she wouldn't have one at all because of fetish-less dad? I N T E R E S T I N G