How old is Kawakami?

I know this question gets asked often here, but i am in a middle of an argument with someone else. I told another person she is in her thirties since that is what the official art book says when her design comes to mind. Another person comes in and says she is in her twenties, but because she doesn't take care of her looks, she looks older than what she actually is. He also refers to Kawakami referring to herself at the end of her social link as a "young adult" and according to him, Japanese people consider you as a young adult up in your twenties.

So is there any actual evidence in how old Kawakami is actually supposed to be instead of just speculation? Also what age range do you consider to be a "young adult"?

I know this question gets asked often here, but i am in a middle of an argument with someone else. I told another person she is in her thirties since that is what the official art book says when her design comes to mind. Another person comes in and says she is in her twenties, but because she doesn't take care of her looks, she looks older than what she actually is. He also refers to Kawakami referring to herself at the end of her social link as a "young adult" and according to him, Japanese people consider you as a young adult up in your twenties.

So is there any actual evidence in how old Kawakami is actually supposed to be instead of just speculation? Also what age range do you consider to be a "young adult"?