Takeru Ooyama (大山 タケル Ooyama Takeru) is a member of the Student Council Security Division, a freshman student at Tenbi Academy, and the central protagonist of the Maken-Ki series. He is the child of Takeshi Ooyama and Atsuma Ooyama, descendant of Oousu no Mikoto and Yabiko Ooyama, and very distantly related to Kodama Himegami.
Takeru originally enters Tenbi Academy without any knowledge of the school, other than that the school had changed from all-girls to co-ed. Before moving to Tenbi, he was at an all-boys school. His best friend is Kengo Usui. He currently lives with Haruko Amaya, Kodama Himegami and Inaho Kushiya.