If you're looking for manga similar to Shin Gakkou no Yuurei, you might like these titles.
Once upon a time there was a king who ruled by fear. Upon discovering the existence of the Goddess of Destruction he resurrected her, but this only lead to the destruction of his own country. As a result of the carnage, she was sealed in a box that was kept in a very deep, dark place. The box was locked with many keys that were then spread across the world.
Young Kurumi has never received presents on her birthday. Over the years, she has also never aged and credits her longevity to the fact that she has never opened a present. Now it is her role to travel the world, bestowing gifts on others. But these presents never turn out to be what the recipients desired; there's always a dark side and a high price to pay.
Dark Dimension Zero is a tale of young Zero, a half devil-half god who has been given the duty of coming to claim the souls of the living once their time has come. In this first tale, Zero comes for a young girl, who has plunged off the side of a building going after the most precious posession in her life, a book. Can love guide her back to the realm of the living, or will this trip into eternity be permanent?