grandchild, descendants
孫 centers on the relationship of a child's child: a grandchild, and by extension one's descendants further down the family line.
孫 combines 子 (child) with 系 (lineage, connection), suggesting a child further down the family line. The exact historical development of 系 as a phonetic or semantic component is uncertain.
A child 子 connected by a family line 系: that child's child is your grandchild, a descendant.
For ソン, imagine a grandchild proudly showing off a sonogram picture of their own future child: son -> ソン, and the family line continues.
grandchild
descendant; progeny; offspring
Sun Wukong (character in the classic Chinese novel Journey to the West); Monkey King
granddaughter
children and grandchildren; posterity; descendants
grandchild
great-grandchild
descendant of a god; heavenly grandson
great-great-grandchild; fourth-generation descendant
first grandchild
backscratcher
one's descendants; one's offspring; posterity
seventh-generation descendant; great-great-great-great-great-grandchild
your grandchild
children and grandchildren; descendants
child of one's heir
grandchild from a daughter married into another family
the descent to earth of the grandson of the sun goddess
grandniece; grandnephew
eldest son's descendants