The circumstances of Sanshirō's lending money to Yojirō were as follows.
Around nine o'clock on a recent evening, as rain was falling, Yojirō had shown up unexpectedly. He immediately confided that he was very much in a bad way. His complexion, to be sure, was unusually pale. Sanshirō assumed it was the cold rain and the autumn chill. As Yojirō settled himself, however, it was apparent that the problem went deeper. He was uncharacteristically reticent.
"Are you really unwell?" Sanshirō asked.
Yojirō fluttered the lids of his deer-like eyes. "Actually, I've lost some money. I'm in trouble."
So stating, his face took on a worried expression as he expelled several columns of smoke from his nostrils. Sanshirō felt compelled to say something. He asked what kind of money it was and where Yojirō had lost it. The answer was immediately forthcoming. Yojirō had only refrained long enough to dispense with his smoke. After exhaling, he proceeded to relate the entire story in detail.
Yojirō had lost twenty yen. However, it wasn't his money. The prior year, when Professor Hirota had moved into his previous house, he'd been unable to come up with the three months' security deposit. To cover the shortfall, he'd borrowed from Nonomiya. The money he'd borrowed, though, was money that Nonomiya had had his father send from the country so he could buy his younger sister a violin. While immediate repayment was not of the essence, the longer it was delayed the longer Yoshiko waited. To this day, in fact, the Professor had not returned the money, and Yoshiko was still without her violin. If the professor had the money, he no doubt would have settled. He barely scraped by on his monthly pay, though, and he was hardly the type to take a side job, so the debt remained. Then, over the summer, he'd agreed to grade high school applicants' examination papers. This task paid sixty yen, which he'd finally received. Able at last to fulfill his obligation, he'd assigned the errand to Yojirō.