Koi to Obake no Sodate Kata

Yorito's parents and their familiar Rurimaru died ten years ago, fighting against evil majinas; and his older brother was injured. Now it is Yorito's task to protect the village against the majinas together with his familiar Himaru. But he is still only 18 years old and Himaru is still weak. He wants desperately to grow strong and be able to protect his older brother. But it seems his older brother is keeping something from Yorito.