About the name Seiji
Seiji belongs to the Japanese tradition. Its roots are documented, even though its precise meaning is not recorded in the standard references — an honest gap we prefer to a confident guess.
In the United States, Seiji first appears in Social Security records in 1914. It climbed to its best-ever rank of #2565 in 1925, and in 2024 8 babies received the name — 509 in total since 1880. Those are the official counts, not estimates.