Stories of the Japanese 00494 [Late Heian Period] The End of Yoshitaka

Although the Battle of Ichi-no-Tani chronologically comes first, I will prioritize clarity and change the order to look at the tragedy of Kiso Yoshitaka first.
With Yoshinaka confronting Yoritomo and dying in defeat, the position of Yoshitaka, Yoshinaka's surviving son who had been sent as a hostage, became extremely precarious. Yoshitaka was originally sent as the fiancé of Yoritomo's eldest daughter, Ohime, but now that Yoshinaka had died in defeat, it became uncertain whether that engagement remained valid.
Incidentally, at this time, Yoshitaka was 11 years old and Ohime was 6. The very concept of an engagement seems a bit premature, doesn't it?
Yoshitaka and Ohime had spent time together as closely as siblings, but 6-year-old Ohime, upon hearing of Yoshinaka's death, feared that Yoshitaka would also be killed.
On April 21, 1184, Ohime encouraged Yoshitaka to escape Kamakura and helped him. She prepared a boy of the same age as Yoshitaka to impersonate him, while the real Yoshitaka disguised himself as a lady-in-waiting and slipped out of the residence surrounded by Ohime's attendants.
However, as it was a plan devised by an 11-year-old and a 6-year-old, it was quickly discovered, and Yoritomo mobilized all his retainers to search for Yoshitaka. There was a possibility that Yoshinaka's surviving retainers might rally around Yoshitaka to start a large-scale rebellion, so Yoritomo likely could not leave the matter as it was.
On April 26, Yoshitaka was captured at Irumagawara in Musashi Province (Iruma City, Saitama Prefecture) and killed by Tounai Mitsuzumi (?-1184). It was a short life of 11 years.
Upon learning of Yoshitaka's death, Ohime was so grief-stricken that she could not eat and fell ill. Ohime would continue to suffer from mental illness for the rest of her life, and the experience of losing her fiancé must have been far too cruel for a 6-year-old girl.
It was Hojo Masako who was enraged by this treatment by Yoritomo. On June 27, Masako said,
"Even if it was your husband's order, why did you not consult me?"
She was angry, sentenced Tounai Mitsuzumi to death, and had his head displayed. It is unclear why he was sentenced to death when he had merely followed Yoritomo's orders, but Kamakura at the time was likely a society of that level, lacking the concept of a state governed by law.
Furthermore, Masako built a shrine at the place where Yoshitaka was killed (Sayama City, Saitama Prefecture) to mourn him. That shrine is now known as "Shimizu Hachimangu," and it enshrines Yoshitaka as its deity.