Did Koshi Inaba Build a Retreat Larger Than Tokyo Dome? Examining Celebrity Mansion Myths

If built in reinforced concrete, it could cost over ¥1 billion

There were reports that a villa being built by Koshi Inaba (61) of B’z in Karuizawa is so extravagant that it has drawn complaints from local residents.

According to “Weekly Shincho,” the property covers about 5,000 square meters—slightly larger than the Tokyo Dome’s footprint—making it a remarkable project even by local standards. The article states that, in addition to the main residence, the site includes log cabins, an open-air bath, a gym, and a recording studio.

A local real-estate agent quoted in the article estimated the land value at just under ¥400 million. The buildings themselves could cost ¥500–800 million if constructed in wood, or more than ¥1 billion if built with reinforced concrete. By any measure, it is an extremely luxurious development.

From the article, it does not appear that any specific disputes with local residents have actually occurred. However, there are concerns that the project could potentially conflict with Karuizawa’s environmental preservation guidelines.

When people think of celebrity status symbols, lavish homes are often near the top of the list. In the days before social media, celebrities would sometimes invite magazine coverage of their homes or even showcase them on television. To some extent, such homes were a source of pride.

Magazine features showing aerial photos of overseas celebrities’ mega-mansions, or grand estates owned by famous actors in upscale Japanese neighborhoods such as Den-en-chofu and Seijo, were popular. Television programs that introduced celebrities’ homes also attracted strong ratings.

A director from a commercial TV variety program explains:

“Luxury homes have always fascinated ordinary people, and programs featuring them generated a lot of interest. These days, however, we avoid showing the exterior of houses. With the rise of anonymous criminal groups and home-invasion robberies, the risk of making someone a target has become much greater. Even if it’s not a mansion, viewers are interested in where celebrities live, so programs that focus on the interior still perform well.”

Popular entertainers are also often surrounded by mansion-related rumors whose truth is difficult to verify.

In Inaba’s case, stories about luxurious properties have circulated for years. Separate from the Karuizawa villa, he is said to still own an impressive residence in an exclusive residential area.

About fifteen years ago, information circulated among the media claiming that Inaba was building a mansion in Rokurokuso, an ultra-exclusive neighborhood in Ashiya, often described as western Japan’s equivalent—or perhaps something even grander than—Den-en-chofu.

The writer recalls visiting the site after hearing reports that it was being built as a tax-saving measure. Surrounded by high walls, the property could not be fully seen, but through an open gate, a tennis court and swimming pool were visible.

Later, however, it emerged that the house did not belong to Inaba at all; it was reportedly owned by someone associated with B’z’s management company.

And Inaba is not the only one. Stories surrounding his bandmate Tak Matsumoto are said to be even more extraordinary.

There were even sightings reported around Lake Biwa

When Osaka’s ABC TV (Asahi Broadcasting Corporation) relocated its headquarters in 2008, rumors circulated that Tak Matsumoto had purchased both the former headquarters site and the adjacent hotel property.

According to the story, Matsumoto planned to build a recording studio there. In the end, however, a high-rise condominium tower was constructed instead. The rumor turned out to be completely unfounded.

Among celebrities surrounded by extravagant-home legends, however, none seem to attract more stories than Takuya Kimura.

It is well known that after marrying Shizuka Kudo, Kimura initially lived with her parents at her family home. At the time, though, persistent rumors claimed that the couple was building a new residence.

Information circulating among reporters placed the supposed house in Chiba Prefecture, in a seaside town not far from Kimura’s hometown.

Following the lead, the writer visited the location and found a Provence-style house with orange exterior walls and a blue roof. A golf course was nearby, and the beach was only a short walk away. Since Kimura enjoys both golf and surfing, and the house seemed like something Kudo might appreciate, it all sounded plausible.

However, further investigation revealed that the property belonged to a well-known software company based in western Japan. The writer reportedly staked out the location for several days, but naturally neither Kimura nor Kudo ever appeared.

Another famous rumor claimed that Kimura had purchased the penthouse of a resort condominium overlooking Lake Biwa.

Among media circles, there were also frequent stories that Kimura was an expert black bass fisherman. Since black bass are abundant in Lake Biwa, rumors spread that he often visited the area, and alleged sightings began to emerge.

The story eventually took an unexpected turn. It turned out that a man living in the Kansai region bore a striking resemblance to Kimura and frequently went bass fishing at Lake Biwa. The writer was shown a photograph of the man and admitted that, from a distance, he could indeed be mistaken for Kimura, although he was considerably older. Later, it was discovered that the penthouse in question actually belonged to the chairman of a famous corporation.

On another occasion, a Kansai-based comedian reportedly told the writer:

“Looks like Kimutaku lives in Minoh.”

According to the comedian, Kimura was supposedly originally from Minoh and still had relatives there.

The writer had never heard such a claim before, and it appeared to have no factual basis whatsoever. Most likely, it too grew out of mistaken sightings of Kimura’s look-alike.

The comedian even joked:

“I guess idols want to return to their hometowns when they get older.”

But the most extreme rumors came from Okinawa.

One day, while riding in a taxi, the driver pointed to an elegant resort condominium and said:

“That’s Kimutaku’s place.”

When asked whether he had ever actually seen Kimura there, the driver replied:

“I haven’t, but my friend says he sees him all the time.”

On another day, a different taxi driver pointed to a large but somewhat older apartment building and confidently declared:

“Did you know? That’s Kimutaku’s home.”

The driver went on to claim that Kimura had also purchased another condominium in northern Okinawa.

None of these stories were supported by evidence; they were simply local rumors whose truth could not be verified.

Still, the fact that such stories seem to spring up everywhere may itself be proof of Kimura’s status as a genuine superstar.