Searching for Japanese friend

Hello, my name is Sandy and I was living in Japan 1970 to 1972. My Dad had us over there while he was stationed in the Air Force there. I had a friend named Keiko Sonobe. She lived in Ibaraki at the time. She had attended the Ibaraki Christian College. I was aged 13 to 15 years old back then. Please let me know if anyone would know how I can get in touch with her. It has been so many years.,

Thank you so much