This letter proposes two methods to improve the iterative hard-reliability based majority-logic decoding algorithm for non-binary low-density parity-check (NB-LDPC) codes. The first method improves the error-correcting performance by modifying the initialization process, which is based on the fact that Gray coded modulation is used in general. In addition, a storage reduction method is proposed to make the proposed decoding hardware-friendly, which reduces the memory size considerably while sustaining the error-correcting performance achieved by the modified initialization. For an NB-LDPC code over Galois field of 32 elements, the memory size is reduced by about 75% compared with that of the conventional decoding algorithm.