Misato Mikami

Misato is actually Miyuki's biological mother, who infiltrated the organization and worked her way up to learn the leader's name. She was about to with a certain mission—killing Fiasse Crystela—but was stopped by her own children. She then left and became the leader of Hong Kong Defence Group. In the OVA, Misato is the commanding officer of the Hong Kong Intelligence Defence Squad's 4th Division, and plans to recruit Kyouya and Miyuki into her team.

(Source: Wikipedia)