Survey 1 (%)	Survey 2 (%)	Survey 3 (%)
Number of respondents	4698	6855	2472
Number of survey questions	383	401	174
Residence
10 prefectures with big cities	2783 (59.2)	1520 (22.2)	1102 (45.6)
37 prefectures without big cities	1915 (40.8)	5335 (77.8)	1370 (55.4)
Gender
Men	2283 (48.6)	4404 (64.2)	1626 (65.8)
Women	2415 (51.4)	2451 (35.8)	846 (34.2)
Age
10s	790 (16.8) *	36 (0.5) *	7 (0.3) *
20s	759 (16.2)	460 (6.7)	125 (5.1)
30s	785 (16.7)	1038 (15.1)	346 (14.0)
40s	783 (16.7)	1726 (25.2)	610 (24.7)
50s	777 (16.5)	1740 (25.4)	626 (25.3)
60s	804 (17.1)	1236 (18.0)	480 (19.4)
70s and older		619 (9.0)	278 (11.2)
Marital status
married	2172 (46.2)	4074 (59.4)	1418 (57.4)
unmarried	2301 (49.0)	2242 (32.7)	846 (34.2)
separation	225 (4.8)	539 (7.9) **	208 (8.4) **
Occupation
executive of a company or association	44 (0.9)	123 (1.8)	53 (2.1)
office worker, staff of an association	1386 (29.5)	2085 (30.4)	734 (29.7)
part-time employee, contract employee, dispatched labor	206 (4.4)	1196 (17.4)	433 (17.5)
part-time worker, part-time job, home-based workers without an employment contract	585 (12.5)	17 (0.2)	7 (0.3)
civil servants	140 (3.0)	253 (3.7)	68 (2.8)
self-employed, family employee, freelance	286 (6.1)	818 (11.9)	294 (11.9)
faculty member		123 (1.8)	39 (1.6)
student	795 (16.9)	95 (1.4)	26 (1.1)
homemaker	700 (14.9)	766 (11.2)	292 (11.8)
pensioner	147 (3.1)	603 (8.8)	267 (10.8)
none	365 (7.8)	690 (10.1)	240 (9.7)
others	44 (0.9)	86 (1.3)	19 (0.8)
Education
currently attending high school	351 (7.5)	43 (0.6)	7 (0.3)
currently attending vocational college, specialized training college	75 (1.6)	84 (1.2)	26 (1.1)
currently attending junior college, college	48 (1.0)	47 (0.7)	8 (0.3)
university/college preparatory school	14 (0.3)	4 (0.1)
currently attending university	366 (7.8)	88 (1.3)	35 (1.4)
currently attending a Master’s or Doctoral course	22 (0.5)	19 (0.3)	3 (0.1)
junior high school	70 (1.5)	175 (2.6)	50 (2.0)
high school	997 (21.2)	2153 (31.4)	664 (26.9)
vocational college, specialized training college	370 (7.9)	638 (9.3)	240 (9.7)
junior college, college	404 (8.6)	598 (8.7)	217 (8.8)
university	1778 (37.8)	2657 (38.8)	1081 (43.7)
more than a Master’s degree	203 (4.3)	349 (5.1)	141 (5.7)
Notes: * In Survey 1, the 10s were 16, 17, 18, and 19 years old, while in Surveys 2 and 3, the 10s were 18 and 19 years old. Details of Survey 1 are as follows: 313 16- and 17-year-olds (6.7%) and 477 18- and 19-years old (10.2%). ** divorce 418 (6.1)/death 121 (1.8). ** divorce 161 (6.5)/death 47 (1.9).