Efficient node repair is a crucial problem in erasure-code-based distributed storage systems. An important metric for repair efficiency is the I/O cost which means the amount of data accessed at helper nodes during the repair process. However, minimizing the I/O cost might not directly correspond to an optimized I/O unless the data reads are sequential. In this work, we construct a family of (n,n-r;r^2) MDS array codes where each node has an uncoded and sequential-access repair scheme. We call MDS codes possessing this property as access-friendly ones which are of practical importance. Since the sequential-access repair is realized at a higher sub-packetization level, our codes reach lower I/O cost (or bandwidth) ratio than existing access-friendly MDS codes.