Memory device and memory system

A memory system comprising:

• a memory device;
• and
• a controller that controls the memory device,
• the memory device being provided with n-number of memory cell units that are provided on a substrate and stacked in order as a first memory cell unit to an n-th memory cell unit in a first direction, the n-number of memory cell units each including
• one or more first electrodes,
• a plurality of second electrodes each provided to intersect the first electrode,
• a plurality of memory cells provided at respective intersections of the first electrode and the plurality of second electrodes, the plurality of memory cells each coupled to both of the first electrode and a corresponding one of the second electrodes, and
• one or more lead lines that are coupled to the first electrode to form one or more coupling parts, the one or more coupling parts in an (m+1)-th memory cell unit of the memory cell units being located at a position where the one or more coupling parts and an m-th memory cell region overlap each other in the first direction, the m-th memory cell region being surrounded by the plurality of memory cells in an m-th memory cell unit of the memory cell units, where m denotes a natural number equal to or smaller than n, wherein the one or more coupling parts in the (m+1)-th memory cell unit are located at a position where the one or more coupling parts and the plurality of memory cells in the m-th memory cell unit overlap each other in the first direction.