Kosaka Jinnai-jinja

“A cure for malaria?” you might scoff. But in 17th-century Japan, such a cure was desperately sought after. Here at Kosaka Jinnai-jinja, we uncover a tale of a swordsman, a thief, and a surprising promise. Kosaka Jinnai-jinja isn’t dedicated to a deity, but to a man. Jinnai Kosaka was a figure shrouded in mystery. Some say he was a samurai, others whisper he was a ninja of the Takeda clan, perhaps even a student of the legendary Musashi Miyamoto. He became a mercenary in the Kanto region, hunting down remnants of rival clans. His most famous capture was his nemesis, the ninja-turned-thief Kotaro Fuma. Kosaka Jinnai’s deeds made him a hero to some. However, the shogunate saw him as a threat. In 1613, they captured him. Before his execution, Jinnai, weakened by malaria, made a bold claim. He declared that if not for the disease, he would have escaped. He vowed his spirit would linger, healing those who prayed to him for relief from malaria. A shrine arose near his execution site, a testament to his final words. Kosaka Jinnai-jinja became a place of pilgrimage for those seeking a cure. The original shrine was destroyed in the Great Kanto Earthquake of 1923. It was rebuilt in 1930, not at the original location but nearby, ensuring Jinnai’s legacy lived on. Even today, people visit Kosaka Jinnai-jinja, paying respects and seeking good health. They remember the swordsman, the thief, and his promise of healing.