Iwasada will be donating money to earthquake relief and youth baseball organizations in Kumamoto, his home prefecture. He will donate 100,000 yen for every game he wins and a box of rubber baseballs for every strikeout he records. The money will be donated in person, some time between November 2017 and January 2018.
Source: Hanshin 3/28/2017
Iwasada is throwing four kinds of balls (a regular baseball, a soft ball with stitching, a sponge ball, and a golf ball) as part of his training this winter. All of the balls, other than the golf ball, are about the same size. Throwing the different kinds of balls is supposed to help him find his optimal release point.
Iwasada is going to hold off on gaining weight during the winter because he found it did not work for him this year. He managed to push his weight to eighty-eight kilograms for spring camp this year, but he felt it was too much and did not work for him. For now, he plans to keep his weight at eighty-one or eighty-two kilograms.
Iwasada visited the Kumamoto government offices on December 27, 2017 and donated 500,000 yen to the prefecture (100,000 yen a victory, five victories this past season). He also donated ninety-three boxes of rubber baseballs (one box per strikeout, ninety-three strikeouts) to youth baseball players in Mashiki, Kumamoto.