This article investigates the abrupt jump in the number of suicide cases in Japan in 1998 and the subsequent persistency of this figure by utilizing a generalized decomposition formula. In particular, by considering the change in the demographic structure, we decompose the 1998 jump in the number of suicides and the cumulative changes from 1998 to 2007 by age and gender. Our results show that while the abrupt jump in the number of suicides in 1998 is mainly attributed to middleaged males, who are 40 to 59 years old, the consistently high number of suicides after 1998 is because of the suicides of people from the younger generation, i.e., the age group from 20 to 39 years. This "juvenization" in suicides is also reflected by the change in the means for committing suicide. Finally, aging is also identified as an impediment in combating the high suicide numbers.