Abstract: The present invention proposes a self-standing housing body solving a typical program and stably standing as a penholder. Specifically, the self-standing housing body according to the present invention is a self-standing housing body including a housing portion having a main housing space surrounded by a bottom surface and side surfaces standing from the bottom surface, and a lid portion having a sub-housing space surrounded by an upper surface and side surfaces standing from the upper surface. An upper side of one side surface of the housing portion and a lower side of one side surface of the lid portion form a joint portion, and about the joint portion as a rotation axis, the lid portion is rotatably joined to the housing portion.

Abstract: The present invention provides a sharpening completion detection mechanism that does not apply a heavy load to a core tip, and especially proposes a mechanism that moves a pencil in an ejection direction immediately when the sharpening completion detection mechanism detects completion of sharpening to mitigate damage to the core.