TOKYO >> Time is running out for an iconic Tokyo building that, for the romantic, stands as a futuristic symbol of a bygone era, and for the pragmatic, represents an eyesore well past its prime.

For nearly half a century, the Naka­gin Capsule Tower has been turning heads for its idiosyncratic, building-block design that has become a heralded landmark on the Ginza skyline. It had survived previous attempts at demolition, prompted by concerns over crumbling concrete and dubious compliance with modern seismic codes. But Nakagin’s upcoming sale to a real estate developer intent on replacing the beleaguered building may prove to be the decisive blow that brings the towers tumbling down, to the dismay of the people who have campaigned to save this piece of architectural history. As the few remaining residents of the towers begin vacating their cramped premises, the fate of the towers continues to hang in precarious balance.

Completed in 1972, the Nakagin Capsule Tower is actually two interconnected towers, suspending 140 modular “capsules.” It is the ultimate calling card of architect Kisho Kurokawa (1934-2007), and the building is revered as a rare extant example of the largely theoretical Metabolist school, one of the first architectural movements to emerge from the ashes of postwar Japan at the 1960 Tokyo World Design Conference.

As a founding Metabolist, Kurokawa was influenced by biological processes and sought to create buildings that would organically evolve with the changing needs of its residents and the city. Yet none of the capsules at Nakagin were ever replaced. Their age shows. Over the decades, the structure has fallen into notorious disrepair. The integrity of the towers’ cores has run afoul of seismic regulations revised after the catastrophic earthquake that hit Japan in 2011.

At a meeting of the building’s management in March, capsule owners voted to sell the towers — and the prime land underneath — to a real estate developer keen on razing Naka­gin in order to erect a new mixed-use office and residential complex. Under the proposal, demolition work would start in March, with construction to be completed by November 2024.

The building’s board had previously voted for demolition in 2007, but the plans were scrapped in 2009 after the general contractor behind the proposal went bankrupt. Following the incident, the board again faced gridlock between pro-preservation and pro-demolition residents — that is, until the property owner began snapping up units to tip the scales in favor of demolition.

But there is still a faint glimmer of hope for Nakagin. Demand for new property development has stagnated since the start of the pandemic, and it is possible that the terms of the proposal could change if an investor were willing to bring the building up to code.

A group of residents and enthusiasts continue to search for such a person under the banner of the Naka­gin Capsule Tower Preservation and Restoration Project. Although the group had been brokering talks with promising candidates, including an overseas investor committed to the conservation of historic buildings, a solution that pleases all parties has remained elusive.

Perhaps even more appreciated abroad than in Japan, the photogenic building was, before the pandemic, the site of a pilgrimage for architecture students and tourists.

“There is an endless stream of people interested in taking tours of the building, but we’re now in a very difficult position,” lamented Tatsu­yuki Maeda, leader of the Preservation Project and the owner of a handful of capsules himself. “It’s a pity.”