A Swedish man has become an unlikely protector of ancient Japanese swords by learning the art of sword-crafting, overcoming numerous setbacks including the major earthquakes that rocked Kumamoto in 2016.

Hans Koga, 45, also known as Hansuke Koga, lives in Nagomi, Kumamoto Prefecture, and is one of the rare "koshirae" craftsmen specializing in meticulously repairing the exterior, including the handle and sheath, of Japanese swords.

The southwestern Japan prefecture is where Higo koshirae originated, a sword style established by Hosokawa Tadaoki (1563-1646), father of the first lord of Kumamoto.

By replacing old and damaged sword handle wrapping and other parts to make the sword last another hundred years with its original look, Koga told Kyodo News he is playing a "part in contributing to cultural history."

"I am only interested in this culture. This is my work."

As a child in Stockholm, Koga developed an interest in Japanese swords after he discovered Iaido, a Japanese martial art that involves drawing a sword, and began collecting them.

Koga came to Japan in 2012 after injuring his hand and leaving a career as a ship builder. He received training for craftwork associated with Japanese swords at a Tokyo studio, during which he became interested in Higo koshirae, a style that attracted him by its simplicity and functionality.

In the fall of 2015, Koga moved to Kumamoto, where after discovering there was no active Higo koshirae craftsmen, he asked a retired craftsman to train him.

Then a magnitude-6.5 earthquake hit the region on April 14, 2016, and a M7.3 temblor two days later, subsequently killing over 200 people and leaving thousands more injured. Koga's home, which he used as a studio, also collapsed in the disaster.

Despite the setback, Koga decided to stand his ground and stay in the prefecture, thinking there would be no keeper of the tradition if he left.

Now having taken on an apprentice from last year, Koga says he is even more determined to keep the tradition alive.

When repairing an old Japanese sword, Koga carefully takes it apart, cleanses its original strings and shark skin, and then binds the parts together. He methodically follows the traditional ways, including using lacquer as glue.

What worries him is the rise -- as the population of the koshirae craftsmen declines -- in a number of repairers who alter the swords' original look.

Once a sword is repaired in a different style, its original appearance will be forgotten and lost forever, he says.

"I choose exactly the same color and replace (parts) to (make the sword) look exactly the same as it was."