Japanese Task Force

The Japanese Task Force, (commonly referred to as the Task Force, or Kira Investigation Team) is the primary organization searching for Kira.

Overview
The Task Force was created by L after he deduces that Kira is in Japan, and is the only organization within the country that is searching for Kira. The existence of the organization is not made public, and the names and personal information of all of the members' is kept secret. After L's death Light Yagami heads the organization, and begins operating as 'L'.

The NPA initially had many members on the Kira case. After it becomes clear that anyone searching for Kira would be in great danger, the officers are given the choice to stay or leave. It is made clear that if they leave, they do not lose their job or paycheck, they simply will no longer be assigned to the Kira case. They are told to make the choice carefully, and to take their family into consideration.

Nearly every member decides to leave the case. The members left are addressed by L via computer, who says that he will meet them face to face. L in fact had been waiting for the other members to leave, knowing that those who stayed would be dedicated to the investigation.

L
L is the creator and leader of the Task Force. He is considered in-universe to be the world's greatest detective. His primary objective is to bring Kira to justice at any cost.

Light Yagami
Light Yagami is Kira, and he joins the Task Force in order to get close to L and discover his real name. His intelligence is on par with L's.

Soichiro Yagami
Soichiro Yagami is Chief of the NPA, and Light Yagami's father.

Shuichi Aizawa
Shuichi Aizawa leaves the Task Force after the NPA discontinues to provide funding. When Aizawa announces that he's leaving in order to keep his job with the NPA, L withholds the fact that he has already set aside the funds needed for each Task Force member in advance in order to test his loyalty. Aizawa ultimately leaves the Task Force, refusing to work with L. He returns before L's death, and later becomes one of the first people to suspect Light Yagami of being Kira. After the Kira case ends, Aizawa becomes Chief of the NPA.

Kanzo Mogi
Kanzo Mogi is one of the most dedicated members of the Japanese Task Force, but also one of the most reserved.

Touta Matsuda
Touta Matsuda is an inexperienced, yet dedicated member, who wants to solve Kira's case no matter what.

Hideki Ide
Hideki Ide helps coordinate their efforts, and performs actions such as organizing a blockade of police cars.

Hirokazu Ukita
Hirokazu Ukita is the most emotional member of the Kira investigation.