We investigate an intriguing scheme to realize nonreciprocal frequency combs in a compound system comprising a YIG sphere and two coupled whispering-gallery-mode microring resonators. The phase-matching condition is satisfied when the driving fields of the two resonators are in the same direction and vice versa. Numerical simulations of the cavity magnonic dynamics show that the frequency comb exhibits significant differences due to the asymmetry of the nonlinear response in different directions. Furthermore, the proposed scheme offers greater flexibility compared to conventional cavity magnonic systems, allowing easy tuning of the number of frequency combs (i.e., tuning of the nonreciprocal strength) by adjusting the two-photon driving strength. In addition to elucidating optical nonreciprocity in cavity magnonics, this research may also find potential applications in optical frequency metrology and precision measurements.