Name : Sinobi Gashir
Age : 42 (deceased)
Rank : Shinobi Gashira (Head ninja, probably Jonin-level)
Height : 177 cm
Weight : 70 kg
Birthday : April 2
Blood Type : O
The head ninja's true name is unknown, although many people call him Shinobi Gashir as the result of a mistranslation. Although he's called Kumo no Kuni no Shinobi Gashira in the First Data Book, there's no such country as Kumo no Kuni in Naruto, although there is a village named Kumogakure which lies in Land of Thunder. The Shinobi Gashira is, however, listed under Kumogakure's village symbol.
Sinobi Gashir sent to Konohagakure under the guise of the peace treaty between the two villages, the head ninja actually had a hidden agenda. Kumogakure wanted to get their hands on the Byakugan of the Hyuga clan. In order to get the Byakugan, the head ninja tried to kidnap Hinata Hyuga, only to be killed by her father, Hiashi Hyuga. Kumogakure claimed Konoha had broken their newly signed treaty and demanded the dead body of Hiashi as compensation. Although Hiashi was fully prepared to die, he was saved by his twin brother, Hizashi, who volunteered to die instead of Hiashi.