A historic house in Aomori Prefecture supposedly used as a ninja base hundreds of years ago has avoided demolition after its new owner vowed to preserve the property, a university professor said Tuesday.

The wooden one-story house, which sits in a narrow alley in the city of Hirosaki, had faced the risk of demolition, after the couple that owned it for about 30 years decided to sell it due to its high maintenance costs.

However, the house was bought for about ¥20 million by Mitsumaro Sato, a 63-year-old Hirosaki city official, who has agreed to preserve the house and use it to pass on ninja history and culture, according to Shigeto Kiyokawa, a professor at Aomori University who also acts as an advisor to the school's "ninja club."

"We are very glad that we were able to find somebody who is keen to preserve it," Kiyokawa told a press conference.

The house is said to have been built in the late Edo Era (1603-1868) and served as a station for the Hayamichi-no-mono ninja group in the Hirosaki Domain.

It has distinct features, such as floors intentionally designed to make chirping sounds to alert residents of the presence of intruders.

Kiyokawa's initial request that the city preserve the house as a cultural property was met with reluctance, because with the property having undergone remodeling work it was difficult to estimate its cultural significance.