You'll overhear two students in the morning talking about how one of them saw an elementary kid at Naganaki Shrine. After school, you can visit the shrine to find the kid standing there. When you talk to her, she will mention that she's hungry; you'll need to give her a takoyaki from the Octopia stand at Iwatodai. The next time you talk to her, she will mention that she's thirsty; give her a Mad Bull, which can be bought from a vending machine in your dorm. You can establish the Hanged Man Social Link the day after giving her those two items.
Today's correct answer is "SOFT WATER."
