"Kobutori Jiisan" translated directly as "Lump-Taken Old Man" is a Japanese Folktale about an old man who had his lump taken or removed by demons after joining a party of demons (oni) celebrating and dancing in the night.

Japanese folktales are an important cultural aspect of Japan. In commonplace usage, they signify a certain set of well-known classic tales, with a vague distinction of whether they fit the rigorous definition of "folktale" or not among various types of folklore. The admixed impostors are literate written pieces, dating back to the Muromachi period or even earlier times in the Middle Ages. These would not normally qualify for the English description "folktales".