A moderately coupled multicore fiber (MCF) design is proposed with the aim of realizing both low intercore multiple-input multiple-output (MIMO) processing complexity and high-space utilization efficiency. We numerically and experimentally investigated the influence of mode coupling on the intercore differential mode delay (DMD) in homogeneous core MCF, and show a moderately coupled MCF design to avoid increasing the intercore DMD, which enables us to compensate for the intercore crosstalk by MIMO processing with low computational complexity. Finally, we fabricated 125-μm-cladding two LP-mode six-core fiber and experimentally realized the highest normalized channel multiplicity of 18 without a noticeable DMD increase induced by mode coupling.