Beian was given the birth name Sangai (which was written as "三亥" in Japanese) to reflect the fact that the same Japanese Character "亥" appeared three times at the time of his birth, i.e. in the zodiac month, day and hour, hence the use of character for three "三."
安永8年（1779年）、己亥九月、亥の日、亥の刻に江戸日本橋(東京都中央区)桶町に生まれたので三亥と名付けられた。