Chihayafuru

[Ryllharu]

No, Kana isn't using the hakama requirement to promote her family's business and you're right, she's doing it out of love for the clothing. But I suspect that will be the result of her request. Chihaya and she (perhaps Taichi as well) will show up in hakama. If she's wearing something similiar to what she does during the OP, Chihaya's combined skill and appearance will make people feel that she is very elegant, and wonder where she got such a garment.

While Kana isn't doing it for business reasons, there is a likelihood that her family's business will experience a slight uptake. She is unintentionally forcing Chihaya to be a walking billboard. But don't forget that another part of her demands (edit: actually the primary one) was that Chihaya be the model for their catalog/pamphlet. Her family's store essentially got a free Chitose look-alike.