Nothing he tried as a cure was effective, including the pilgrimage of 88 holy places of Shikoku (at that time it was considered a curative ritual for leprosy patients).
While in Kusatsu, he met Englishwoman Hannah Riddell who was vacationing there, and decided to go work at the Kaishun Hospital where she was the director.
He decided to leave the hospital to pursue missionary work in Okinawa at the strong suggestion of Riddell.
However, Aoki himself described Riddell's devotion to her patients, even those who left under difficult circumstances, sending them letters and gifts after their departure.
Aoki and Arato also discovered about 40 people with leprosy who had been forced to live in exile on a tiny island called Jalma.