This kanji consists of three main elements. On the left is the “harvest” (grain) radical. On the top right is a symbol representing stacked rice bales, and on the bottom right is the “shell” radical, which served as currency in ancient times. Together, these elements depict taxes and valuable goods gathered from the people, creating the original meaning “to stack” or “to accumulate.” By extension, this kanji is now used for accumulating intangible valuables, such as gaining experience or building skills.