Jewel Tears

Len, a young man born from wrath and hatred, had promised to his murdered sister that he will revenge her when she was buried. He seeks the murderer, having no leads except for the rivalry between the Kagamine and Hatsune households. Accusing the Hatsunes as the suspects, he slays the entire family one silent night. Just when he thought he killed everyone, he finds a beautiful tealette named Miku trapped inside the underground dungeon. For no reasons, he released her from her cage. Little did he know that it would change every little thing in his future.