She is upbeat, and enjoys making jokes about things, even when she's fighting. She, however, when it comes to investigation and clean-up, never misses anything. This leads her to be quite the investigator. She has a photographic and ideal memory. Making her ideal for clean-up and investigations, she can take apart every little piece of evidence and things she notices in a matter of seconds. She is a master Detective. She is semi indifferent to her partner but she is a controlled woman and never grows emotional in a case. She does have a private life and she thinks that she is more than just a tool once she actually enters that state of mind. She doesn't believe that others have to die and for that reason she does step into bad situations regularly.

Ruku was born into a prominent Tokyo family. Her family owned a large industrial company, and was planning on using Ruku to merge via marriage to the rival industrial family. Though, she was born a little different then them. Although she can see hollows, shinigami and the works, she has never had a bad experience with anyone. Therefore, its not very significant until she joins The Agency.

Ruku during her younger years, and them some, has always been sort of tomboyish. She always tries to be better than boys just so that she can prove her worth to whatever she feels like proving it to. She would beat up on boys who were twice her size. She actually did this with quite the greatest of ease. Over time, fist fights and other types of fights became easy for Ruku, due to the fact that she was able to gain so much experience in fights. Naturally, this never rolled well with her high-class teachers or her parents. She was in trouble about 80 percent of the time, and when she wasn't in trouble, she was picking a fight to get into trouble. Ruku began shooting guns for her own amusement and to blow off steam when she was 10. She began with a 9mm but within a year of practice she had moved onto a .45cal pistol.

When Ruku got into junior high, she was set out to be trained to do her father's work. She didn't like any part of her 'schooling', but she endured thinking that there was a better way after this. The three years of her junior high were intended on making her a business woman. This idea from her father failed miserably. She still continued shooting guns, with accuracy that frightened even the Japanese Police Special Operations. She was firing a .45 like it had no recoil at all. One of the SpecOps handed her his .50cal one day and said she would be much more challenged with the .50cal. She stayed with the man the entire day and night learning how to easily dampen the .50cal's expansive kick.

The first day of high school, Ruku went up to the lead senior, known for beating people up. She asked to fight him. He told her he had no reason to fight a girl like her. Ruku gambled, she said she would be his servant and do anything for the rest of the semester if he beat her. He was on the ground screaming for mercy about a minute later. That day on, no one in her high school messed with her, or even talked to her. While she was kind of satisfied with the results, she did miss conversations. With the four years of practice she got with a .50cal in high school, by the end the recoil was nothing. She came to the realization that the slide on a pistol could never fire fast enough to fire more than roughly .9 shots a second. She called up the man who had been her way of buying guns and asked him to special make a .50cal, single-action revolver. This proved too slow again, she called him up and ordered a different kind of revolver, a breach loadable revolver .50 cal, single-action. She spent over three straight months in-between high school and college learning how to load it fast and fire it faster.

It is her freshman year of college and she just finished the detective exams and passed with rather bright colors.

Arcane Bullet Ruku's first soul ability is based around her love of the pistol. The ability is dubbed �Arcane Bullet�. This ability allows Ruku to form very small compressed reiatsu shells which she can load into her Schofield. These are minor shots, and are nothing compared to her later abilities. These bullets CANNOT be infused with additional power.