The helmet used by Kuroda Nagamasa,the first master of Fukuoka Clan. It originally belonged to Fukushima Masanori,a warlord. However,it is believed that this helmet was exchanged with the one in design of buffalo horn which had been a favourite of Nagamasa. The shape is derived from hisrorical allusion that Minamoto Yoshitsune won the battle of Ichinotani by climbing down the steep valley.