One embodiment of the present invention relates to an article of open-toe footwear including a sole member and a modular retaining system that allows a user to affect the appearance and function of the article of footwear. The modular retaining system includes a strap member and a plurality of coupling members. The strap member extends from an upper surface of the sole member over a corresponding user's foot between various recesses located on the surface of the sole member. The end regions of the strap member are releasably coupled with the sole member at the recesses via a releasable engagement with coupler members oppositely oriented within the recesses from a lower surface of the sole member. The releasable engagement between the strap member and the coupling members may utilize a threaded coupling configuration in which a male portion of the coupler member is threadably coupled within a corresponding female portion of the end region.