User blog:NguyenAnhLam/Leo's age

Anyone know that Leo's age is 20000 years old (according to Ultraman Leo (character) page) but I don't understand his age was 20000. So he is the same as Ultraman. But in Ultraman Mebius episode 34 (the episode Leo returns to help Mebius), Gen (Leo's human form) mentions about Taro "Taro-niisan may have approved of you" -> He call Taro like older brother???