was a retainer to the Takeda family towards the beginning of Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

's Sengoku period

Sengoku period

The or Warring States period in Japanese history was a time of social upheaval, political intrigue, and nearly constant military conflict that lasted roughly from the middle of the 15th century to the beginning of the 17th century. The name "Sengoku" was adopted by Japanese historians in reference...

 (1467–1615). He was attacked by Takeda Nobutora

Takeda Nobutora

was a Japanese daimyo who controlled the Province of Kai, and fought in a number of battles of the Sengoku period. He was the father of the famous Takeda Shingen, who was originally named Harunobu, along with two other sons, Nobushige and Nobukado.Nobutora fought Hiraga Genshin at the Battle of...

 at Un no Kuchi

Battle of Un no Kuchi

The Battle of Un no Kuchi was the first major victory for Takeda Harunobu, aged fifteen at the time. He would later take on the name Takeda Shingen, and grow to become one of Japan's most famous warlords....

 in 1536, and forced Nobutora to retreat. But Nobutora's son, Takeda Shingen

Takeda Shingen

, of Kai Province, was a preeminent daimyo in feudal Japan with exceptional military prestige in the late stage of the Sengoku period.-Name:Shingen was called "Tarō" or "Katsuchiyo" during his childhood...

, then 15 years old, and called 'Takeda Harunobu', rallied the Takeda forces and led them to victory, killing Hiraga in the process.