No, the cool idea was having a character who lost all motivation to excel in life, someone completely lost in the boredom of his life that he distanced himself from everyone, including the sister who looked up to him.

The cool idea is her "taking on his life" by becoming what he used to be. Even though it's not what she wants, she's trying to recapture how she used to view him (with respect and admiration).

She hides her actual self, interests and "impurities" from others, and it makes her miserable. It's only when he finds this out does he decide to help her, and he lets her know that she doesn't need to be ashamed about enjoying anime or not being a "perfect" person.

The series (initially and imo) was a comedy about two damaged siblings repairing a very broken relationship with one another, both becoming better and more honest about themselves because of it.