REMOVE

1. Tempered steel
2. Museum of Fine Arts, Boston …
3. Nagamitsu
4. second half of 13th century

WHAT

1. Armor (1)
2. Arms (1)
3. Decorative Arts and Utili … (1)
4. Tempered steel (1)

WHERE

1. Asian; Far East Asian; Ja … (1)

WHO

1. Museum of Fine Arts, Bost … (1)

WHEN

1. 1250 (1)
2. 1299 (1)
3. Japanese; Kamakura period (1)
4. second half of 13th centu … (1)