やがて
The master, who had stopped what he was doing and been listening attentively to the lecture, at this point brakes into a broad grin. I feel I should explain, if you'll indulge me, the meaning of this grin. A cynic, on reading this account, might imagine such grin as tinged with derision. The master's heart, however, is not so tainted. His heart is not so tainted, but neither is he wise in the ways of the world. The reason for his grin is nothing other than sheer joy. After such heartfelt admonition from said ethics instructor, the heretofore indiscriminate shelling of the master's grounds is surely a thing of the past. The master's head would keep its hair. His agitation would not dissolve overnight, but given time it should gradually ease. He could dispense with the damp cloth, dispense with the kotatsu, and there was no need to sleep out of doors. It was such thoughts that delighted the master and elicited a grin. It's only natural that this master of mine, who even in this twentieth century still believes that money lent will be money returned, should hear this lecture and place his faith in its words.
Time was up, it seemed, for the lecture suddenly stopped. In the other classrooms too, lessons were over. As if on cue, eight hundred students, who until now had been bottled up in the classrooms, let loose with whoops and hollers, pouring forth from the building. Their vigor called to mind a large beehive, knocked to the ground and abuzz with great fury. Raising a ruckus, the students spilled out from the windows, out from the doors, out from every crack or crevice, darting unceasingly this way and that. Getting back to our altercations, this is where minor escalated to major.