Tetsutarou Doi was a retainer of the Takasgi Family and friend of Soichiro Takagi before he changed into one of Them.
Tetsutarou Doi is a loyal retainer of Soichiro Takagi and a friend of over twenty years. He was a member of Soichiro's ultra-nationalist group in Tokonosu Prefecture. When the city was hit by the outbreak of Them (zombies), Soichiro used his fortified Takagi Estate as both a base and shelter for his group and other human survivors. It was during one of their rescue missions, members of the group were in need of rescue and he selflessly put his life on the line. Though he saved his friends, he was bitten in the process. He died of his injures and changed. Rather than put him down there, he was caged and brought back to the estate for a special presentation.
The character of Tetsutarou Doi is a supporting character of the manga/anime series Highschool of the Dead that was written by Daisuke Sato and illustrated by Shouji Sato. The series first began serialization in Fujimi Shobo's Monthly Dragon Age magazine in July 2006.
His first appearance was in Hightschool of the Dead Volume 3 CH. 11 "The Dead's House Rules", and his first anime appearance was in Highschool of the Dead - Episode 10 "The Dead's House Rules". His character in the Japanese series is voiced by Daishi Koshiba, and the U.S. dub produced by Section 23 has not yet been credited.
Soichiro brought the caged Tetsutarou into the middle of the estate and had the survivors witness as he told them of the bravery he showed in saving his friend and that they had been friends for many years. Though now he was one of them. One of Soichiro's men ordered the cage to be unlocked and he performed his duty as both leader and friend. Tetsutarou rush and Soichiro quickly cut off his head with a katana. This was a demonstration to the people what was needed in this new world. The will to fight to survive.