Boku no Ushiro ni Majo ga Iru 1-4

Nanri Ryusuke has transferred schools three times this year because of his parents’ divorce and he is determined to make a good impression at this new school because it appears that he's staying for good this time. However, his seat is in front of the weird girl in the class, Fujimori Miya, who claims she is a witch and who everyone in the school avoids. Miya, for some odd reason, takes a creepy interest in Ryusuke and makes him the subject of all her crazy experiments and spells.