This paper analyzes how the recent work-style reform affects Japanese workers' time allocation. Specifically, we examine how and to what extent work hours have decreased in these years, and how much time workers allocate from the extra spare time generated from the decrease in overtime work toward self-training or self-education. Using Japanese time-use data from the 1970s to 2010s, we first observe how time for self-training has changed over 40 years. We point out that time for self-training or self-education of Japanese full-time workers had consistently decreased over these several decades. Second, by using original longitudinal data collected on Japanese full-time, white-collar workers, we look into how the recent work-style reform changed workers' time allocation and whether there was any effect on the time allocated to self-training. We found that workers spent at least some amount of windfall time to self-training. However, the time spent for self-training is very limited, and such observation was only confirmed for workers above 40 years old.