Ever since British sailors brought curry powder into the country at the start of the Meiji Era (1868-1912), curry rice has been one of the most popular dishes in Japan. There are thousands of curry restaurants throughout the country, but only one of them can claim to be a shrine to Slayer, the American thrash metal band known for songs like "Raining Blood" and "Seasons in the Abyss."

Takahiro Kubo, 47, a former television director who dreamed of owning his own restaurant since childhood, opened Calayer in the Minamisenba area of Osaka in 2013, just a short stroll away from the Hard Rock Cafe. Kubo, who also plays drums in a hard rock group called Daughter, decided to name his restaurant Calayer after he noticed the Japanese word for curry shop, kareya, sounded a bit like Slayer, the name of his favorite band.

When Calayer first opened, Kubo prepared more traditional Indian and Sri Lankan-style curries, but always had a strong desire to push the boundaries of flavor. He began experimenting with dashi stock and a variety of spices, herbs, seasonal vegetables and slow-boiled meats.