Tamai took part in the Siege of Port Arthur where he fought under the leadership of 2nd Lieutenant Yuusaku Hanazawa and gained respect for his superior. He also fought in the Battle of 203 Hill along with his division and the other divisions of the Imperial Japanese Army. He was seen furiously firing at the Russian army with Noma close behind him. They were able to take 203 Hill with Tsurumi claiming victory.
Tamai also fought in the Battle of Mukden in Meiji 38 (1905) where he witnessed Hajime Tsukishima attacking their superior 2nd Lieutenant Tsurumi for lying to him. He called out for someone to stop the two of them from fighting. As Tamai helped Maeyama, who had been elbowed by Tsukishima in the face, Tsurumi asked them to leave both him and Tsukishima alone so that they could talk. When Tsurumi and Tsukishima were heavily injured by cannon fire shortly afterwards, Tamai helped carried their bodies and ordered the other soldiers to put Tsurumi on a sledge. They then carried them away to be treated for their wounds.
During a blizzard storm, the 7th Division took shelter in a wooden building as Tamai, Noma, and Hyakunosuke Ogata were resting in a room with a stove.
Was attacked and killed by a bear with his face torn off.