He tossed about a lot in bed in his sleep, and his father, Nariaki TOKUGAWA, thought that this would be a problem when he became the heir to the Tokugawa Family; in order to correct this, razor blades were planted into his pillow (this was done just to scare him, and in reality the razor blades were removed after he had fallen asleep so as to prevent any injuries).
寝相が悪く、父・徳川斉昭が徳川家後継の際に問題になるとして寝相を矯正するために寝るときには枕に剃刀を立てていた（単なる脅しであって、本当に怪我する事の無いように、と眠った時を見計らって剃刀は取り外していたらしいが）。