1992’s portal fantasy Sea of Shadow is the first volume in Fuyumi Ono’s Twelve Kingdoms series. The 2007 English language edition was translated by Alexander O. Smith, and Elye J. Alexander.
Yoko Nakajima’s oddly coloured hair, lighter than any proper Japanese person’s hair should be, makes her an object of suspicion to her parents and schoolmates. It’s true that her hair has been its present colour since birth, and that she is to all appearances a normal, hardworking student and dutiful daughter. But isn’t that just the sort of facade a covert nonconformist would adopt? Her reluctance to assimilate by dying her hair black only underlines here oddity. Although if she did colour her hair, that would also be bad (her school forbids hair-colouring ).
But things could get worse, and do. Accosted by a stranger, given a magic sword and the ability to use it, attacked by monsters, Yoko is transported from Japan to the strange world of the Twelve Kingdoms.