Prohibited to use the following kanji (Chinese character): 仁 (jin [mercy]), 義 (gi [righteousness]), 禮 (rei [courtesy]), 智 (chi [wisdom]), 信 (shin [belief]), 忠 (chu [faithfulness]) and 君 (kun [lord]) for their names.
名前に仁、義、禮、智、信、忠、君の字を使うことの禁止。