>>49478685To begin, the hat is elegant without looking too old-fashioned or being associated with old age. Its wide brim makes it rugged and functional, a adventurer's hat. The brim also hides part of the face, making its wearer seem more mysterious or reserved. The rather plain but noticeable decoration of the hat makes both the adventurous, boyish interpretation and the lady-like, mysterious interpretation work in the proper context, making it a uniquely versatile hat.
The hat's black color makes its wearer appear modest and somber(misdirection, in the case of this hat's wearers), while the white band and ribbon add a sense of delicateness. For Sumireko's hat specifically, the pattern on the ribbon shows her eagerness to stand out and express herself, also portraying her as childish, when compared with Renko's mature contentedness with the plain while ribbon.
Lastly the hat connects multiple generations of the Usami family, making it either a family heirloom or a fundamental trait that Usamis of all generations gravitate to in a sort of eternal return.
What do you have, a grandma hat with ears?