Daitetsu, or Mr. Kunikida, is the Chief Director of the TAC. When Kaede and Momiji were born, Mr. Kunikida raised Kaede like his own daughter, but he exploited her ability to track down and kill the Aragami. However, when Kaede sacrificed herself, he felt heartbroken. With Momiji in the TAC, Mr. Kunikida decides not to exploit her abilities like he did with Kaede and instead treated her like a normal girl.
Source: Wikipedia