RANZAN, Saitama Prefecture--Artifacts labeled as “groundbreaking discoveries” from the ruins of structures associated with warlord Toyotomi Hideyoshi’s Siege of Odawara in 1590 could have been prototypes of ninja weapons.
Akihiro Iwata, an archaeologist and curator at the Saitama Prefectural Ranzan Historical Museum here, said the flat stones and clay balls may well have been the forerunners of “shuriken” throwing stars and “makibishi” caltrops that later made up ninja arsenals.