Michikawa Tadachika served as a bushō during the Sengoku period. He was a retainer of the Kasama clan and the Utsunomiya clan of Shimotsuke Province.
On 9/17 of Tenbun 18 (1549), at the Battle of Kitsuregawa-Sōtomezaka, Nasu Takasuke led 300 soldiers to invade the territory of the Utsunomiya. As a result, upon orders from Ashikaga Haruuji, the Koga kubō, Utsunomiya Hisatsuna led an army of 2,500 men to deploy to the Kitsure River and engage in battle against the Nasu forces.
Initially, the Utsunomiya enjoyed an advantage based on their superior numbers, so Takasuke used troops lying in ambush in Sōtomezaka to create havoc for the Utsunomiya army, reversing the tide of the battle in favor of the Nasu. Tadachika and Takō Nagatomo (a retainer of the Utsunomiya), and the Yokota brothers (five sons of Yokota Tsunamura who were retainers of the Yokota) fought valiantly, halting the assault by the Nasu army, but Tadachika and the Yokota brothers were killed in action. These individuals are known as the Five Brothers of the Yokota.
In an effort to control his army amidst the chaos, Hisatsuna went to the front lines of the battle but died after being struck in the chest by an arrow shot by Ayugase Sanemitsu, a retainer of Iono Sukenobu. The battle ended in victory for the Nasu army led by Takasuke.
Following the death in battle of Hisatsuna, a veteran of the Utsunomiya clan named Mibu Tsunafusa rose-up and seized control of Utsunomiya Castle. After becoming the lord of Utsunomiya Castle, Tsunafusa invited Haga Takateru to use as his puppet while maintaining a grip on power. Senior retainers of the Utsunomiya such as Shionoya Yoshitaka were compelled to submit to Tsunafusa. Nasu Takasuke joined with Tsunafusa while the Utsunomiya clan faced the threat of extinction.