Youhei Nikaidou (二階堂洋平, Nikaidō Yōhei) was the younger twin brother of Kouhei Nikaidou and a member of the 7th Division. He was killed by Saichi Sugimoto and had his intestines taken to cover up his escape.
In Meiji 38 (1905), Nikaidou took part in the Battle of Mukden during the Russo-Japanese War. When 2nd Lieutenant Tsurumi and Hajime Tsukishima were severely wounded, Nikaidou, along with several 7th Division members carried them to a frozen body of water to be carried away on sledges for treatment. They came upon Sugimoto with a dead body who offered to let them use the sledges with one of the Nikaidou twins asking if he was sure. They then brought the two wounded soldiers away to have their wounds treated.
During a blizzard storm, the 7th Division took shelter in a wooden building. While Genjirou Tanigaki and Tsurumi were having a somber conversation, one of the brothers whispered something into the other brother's ear.