Witch Angel

(from ebookjapan):
This SF fantasy depicts the mysterious events involving Kejime Monono, a boy with a twisted face and a dim head, and a beautiful witch angel who haunts him. Kejime Monono is a junior high school student whose school life is ridiculed by the students. A beautiful woman, Rei Tokinowa, suddenly appears in front of him and confesses to Kejime that she loves him, and begins to show her ardent affection for him......?