Mahou Tsukai No Yome. With her mother dead and her father long gone, Chise Hatori spent her childhood going unintentionally from relative to relative, until she finally made her unfortunate way to a strange and unlikely auction block.
Offered as a "Slay Vega" to the highest bidder, Chise is bought by the (literally) boneheaded Elias Ainsworth, who promises to take her as his apprentice.
Elias is a mage, and his world is one of dragons and fairies, but before Chisa can begin to get used to all this, Elias drops another bomb. Apparently, Chise isn't just meant to be his apprentice-she's also going to be his bride.