"Rajomon no oni" or "Rashomon no oni" is an ogre who was said to have lived at Rajo-mon Gate, the main gate of Heiankyo (the ancient capital of Japan in current Kyoto).
羅城門の鬼、羅生門の鬼（らしょうもんのおに）は、平安京の正門・羅城門に巣食っていたといわれる鬼。