Ruin Hunter Raichi (2002)

Lychee, a girl who has lost her memory, and her companion, the mysterious young man 456 (Yogoroo), are traveling in search of the only clue they have left, the Ruins . One day, they learn of ruins where a witch named Habayaga is said to have lived, and arrive at Questar Island, where the ruins are located. What awaits them there...?