Riko acted up set when Takayuki yelled at her to fix her top, I think that was just a reflex action, she would have been embarrassed more if other people had seen her, she took out her frustration on her brother, she doesn't really believe he's a pervert, she uses that automatically to put distance between them, she hides how much she likes her brother to be the same as what she hears from her friends about how they feel about their brothers and boys in general, she doesn't want to take responsibility for how her own actions cause problems with her wardrobe, if a girl lets her know about a problem it's fine, if it's a boy he's a pervert for looking at her and finding the problem, it's like she doesn't want to be seen by boys, when she's older she will go out of her way to attract attention from boys.
Riko acted up set when Takayuki yelled at her to fix her top, I think that was just a reflex action, she would have been embarrassed more if other people had seen her, she took out her frustration on her brother, she doesn't really believe he's a pervert, she uses that automatically to put distance between them, she hides how much she likes her brother to be the same as what she hears from her friends about how they feel about their brothers and boys in general, she doesn't want to take responsibility for how her own actions cause problems with her wardrobe, if a girl lets her know about a problem it's fine, if it's a boy he's a pervert for looking at her and finding the problem, it's like she doesn't want to be seen by boys, when she's older she will go out of her way to attract attention from boys.