It is said that whenever Tokugawa Ieyasu went into battle while carrying this short sword, he would reap great success, as such it was named “Monoyoshi" ("good thing"/"object of fortune").
After Ieyasu’s death, his huge inheritance was split between the three Tokugawa families and several others. This wakizashi, being especially valuable, would be expected to be passed on to the second generation through Hidetada. However, according to records, Kame, the concubine who Ieyasu loved in his final years, despite knowing that the masterpiece sword should be handed down to Hidetada, secretly took the blade and gave it to her son Yoshinao (descended from the Owari branch of the Tokugawa clan) before the inheritance was divided up.
Although the length of the blade would make it a Tantou, the Tokugawa Art Museum categorizes it as a Wakizashi.