Emperor Sujin
The , a national geography completed in 721 AD, says Mount Tsukuba was named after a noble called . According to this account, the area around Mount Tsukuba was once called . Under the reign of (Emperor Sujin), Tsukuha no Mikoto from the was appointed as its governor. He had a strong desire to leave his name in history, so he renamed the area "Tsukuha", which is now pronounced Tsukuba.