How many members are there in the idol group "µ's"?

The answer is 9 because the idol group, commonly known as "s", was specifically created with nine members. The number of members in a group can vary, depending on the concept and intentions of the group's management. In this particular case, the decision was made to have a nine-member lineup, likely for aesthetic and performance reasons, as well as to provide the opportunity for each member to showcase their individual talents within the group dynamic.