I am a BIG kid and yes I too have had bad probs with my parent. They said they didnt want me to be an " Anime losser" for the rest of my life. So what you need to do is just dim it down some and not let them see how much you love it to the point they think you are obsessed over it but tell them it is just a "weekend hobby" and it wont consume your life. I said that and my parents backed down . MWA HA HA!
Ignore all logic and reason to make the impossible possible .......BANKAI!!!!!!!!!