There is no problem if the family member is spouse or young children, who are obviously under support. But if children are grown-up, they may not be considered as dependent family member.
Especially if children have reached coming of age in their mother countries, it mostly will be refused.
It is important to prepare documents showing the applicant actually send children money as an allowance.
It is important that the applicant, who is working in Japan, has enough income to support his/her family, when they come to Japan.
It is necessary to prepare documents such as tax payment certificate and pay slip to prove the applicant has income.
Having family relationship is the requirement.
To prove the relationship, it is necessary to prepare marriage certificate and birth certificate from the official organization.
It needs to pay attention to make sure the family members, who are brought over to Japan, have not had any moral problems such as overstay or illegal employment in the past. If there were problems, it would be difficult to get the status of residence.