Brain tumor problem. The reason for the third girlfriend's amnesia is that she has a brain tumor problem since childhood. Although surgery can solve the problem, the price is that she will lose her memory. "Three-dimensional Girlfriend" (Japanese: 3D Bitv) is a cartoon work by Japanese cartoonist Naboyu. The Dessert, a magazine published by Heart Talk Society, was serialized from September 20 1 1 year to July 20 16, and was issued 12.