As the Emperor Suiko said "masasabi (swords) produced in Kure (Wu-southern part of ancient China) are the best", swords imported from China were mainly used during ancient times.
推古天皇が「太刀ならば句礼（中国の呉）の真鋤（刀剣の意味）」と詠っているように、古代は大陸からの輸入品が主流であった。