Gakuto Oshiro better known by his mononymous stage name Gackt (stylized in all caps), is a Japanese singer-songwriter, musician, record producer and actor.

Gackt was born on July 4, 1973, as the second of three children in a Ryukyuan family, in Okinawa of the Ryukyu Islands, Japan. His father was a music teacher, who primarily played the trumpet, and his mother was also a teacher. Gackt has an older sister and a younger brother. He lived in Okinawa until he was 7 years old (with short periods when was 16 and 26), because of his father's job, living in many different cities on Honshu and Kyushu islands in addition to Okinawa: Yamaguchi, Fukuoka, Shiga, Osaka, and Kyoto. He studied in the Moriyama High School in Shiga, and was enrolled in the Kyoto Gakuen University.