Page "Hōei" Paragraph 5

* February 19, 1709 ( Hōei 6, 10th day of the 1st month ): The wife of Shogun Tsunayoshi killed him with a knife, and then she stabbed herself in the heart.

Tsunayoshi's homosexual interests were aroused by the son of the daimyo of Kai ; and his plans to adopt this Tokugawa youth as his successor were known by a few inside Edo castle.

The shogun's wife, who was also a daughter of the emperor, foresaw that this choice of a successor would be very poorly received by many ; and she feared that it might result in a disastrous civil war.

The shogun's wife did everything she could to dissuade Tsunayoshi from continuing with such potentially divisive and dangerous plans ; and when it became clear that her persuasive arguments were in vain, she resolutely sacrificed herself for the good of the country — she killed her husband and then killed herself.

She may also have done this as she hated the boy.