Noticed this when reading Thorgal recently. My first idea was that these other comics/manga simply copied the idea from Superman (although Dragonball seems to have borrowed from Sun Wukong also). But when looking a bit into it, it seems that at least with Superman the whole "star child" story possibly has a longer lineage. In the chapter "The Orphan in Comics and Graphic Novels" in The Orphan in Fiction and Comics since the 19th Century, Dirk Vanderbeke makes a few arguments relating the early Superman story to Jewish tales and to the Old Testament (hence my mention of Jewish stories in the title), as well as to the then-unfolding holocaust. His arguments include:

• Superman's birth name's possibly Hebrew etymology (relating Kal-El to "God" and "swiftness" respectively)

• Connections with the Jewish legend "The Star Child", which retells Abraham's exile. In it Abraham's birth was announced by a star (Kar-El supposedly meaning "Star Child" in Kryptonese)

• Noah is mentioned as "the sole survivor of a destroyed world", and Moses who was sent down the Nile as a baby to escape "the Pharaoh's mass slaughter of Hebrew children" (as analogues to the young Superman)

• For Vanderbeke "Both saviour figures [Noah and Moses] have to escape mass death, and in 1938, the year of the November pogroms in Germany, the topicality of such tales was evident."

To me some if not all of the associations seem to make sense, also given the Superman's creators Jewish backgrounds. But I'd like to learn more about how accepted such or other interpretations of the "star child" narrative are; and (if possible) about how its influence seems to've spread to other comics.