Abstract: The Egg-shaped stupa represents a distinctive category of monk tomb stupas, implying significant architectural, religious, and artistic merits. The academic community’s assessment of the Egg-shaped stupa and its origins predominantly hinges on its architectural form and the account of Mujaku Dōchū in his “The Object Archive of Zen Forest”, yet lacking documentary substantiation and archaeological findings. Building upon a comprehensive literature review with field investigations and discoveries, this paper delves into the origins and pertinent issues surrounding the egg-shaped stupa, to unveil several key insights. First, the nomenclature of the egg-shaped stupa stems from the stone egg carved onto the stupa’s body, rather than the commonly assumed oval shape of the stupa itself. Second, there exists no direct correlation between the seamless tower and the egg tower, of which the seamless tower possibly has no connection to its literal meaning. Third, there are two variants of eggshaped stupas: one resembling the Buddha’s head, and the other being the true egg-shaped stupa.