Lunar Legend Tsukihime

As a result of a childhood accident that put his life in danger, Shiki Tohno was taken from his family and placed to a relative to raise him. Shiki's father, the head of the Tohno home, passes away years later, when he is a senior in high school, and his sister Akiha, the new head of the household, orders him to move back in. Shiki, however, conceals a terrible secret. He has been seeing lines on items ever since that injury, and the only way for him to stop seeing them is through a particular pair of spectacles. Additionally, he has trouble recalling details from the period before to his accident. On the day he returns to the Tohno family, he comes across Arcueid Brunstud and, in a momentary fit of madness, stabs her in the head with his dagger. Shiki's quest to understand the riddles of his past begins when she unexpectedly reappears beside him later, alive and well, and requests that he serve as her protector.