What is Early Japanese iron-working techniques?

Early Japanese iron-working techniques are known primarily from archaeological evidence dating to the Asuka period. Iron was first brought to Japan during the earlier Yayoi period. Iron artifacts of the period include farm implements, arrowheads, and rarely a knife blade. An ironworking industry likely evolved during the late Yayoi or the Kofun period, when iron weapons and armor became more common. However, the best archaeological evidence for early iron-working techniques in Japan dates to the Asuka period, after Buddhism had been introduced to the imperial court of the Yamato state.