Sexual Behaviors among Individuals Aged 20-49 in Japan: Initial Findings from a Quasi-Representative National Survey, 2022

Figures & data

Table 1. Weighted demographic characteristics of NInJaS respondents, stratified by sex and ten-year age groups.

		Women					Men
		20–29 (N = 1333)	30–39 (N = 1333)	40–49 (N = 1334)	p	20–49 (N = 4000)	20–29 (N = 1333)	30–39 (N = 1333)	40–49 (N = 1334)	p	20–49 (N = 4000)
Age	Mean (SD)	24.6 (3.2)	34.7 (2.9)	44.8 (2.5)	<.0001	36.3 (8.7)	24.8 (3.2)	34.9 (3.0)	44.9 (2.5)	<.0001	36.4 (8.6)
Marital status	Married	21.1	65.5	72.0	<.0001	56.5	15.2	56.6	66.9	<.0001	50.0
	Never married	73.0	30.5	20.8		37.6	80.2	40.3	29.5		46.3
	Previously married	5.9	4.1	7.2		5.9	4.6	3.1	3.5		3.7
Relationship status	Married	21.1	65.5	72.0	<.0001	56.5	15.2	56.6	66.9	<.0001	50.0
	Cohabiting	6.6	1.8	1.0		2.7	3.3	2.0	0.8		1.8
	In a relationship	17.8	5.9	5.1		8.7	12.3	5.3	4.1		6.7
	Not in a relationship	54.5	26.8	21.9		32.0	69.2	36.2	28.2		41.5
Sexual orientation	Heterosexual	75.7	83.8	86.8	<.0001	82.9	80.4	87.4	91.7	<.0001	87.4
	Bisexual	7.1	6.2	3.9		5.5	5.2	3.4	2.2		3.4
	Homosexual	1.5	0.7	0.6		0.9	2.9	2.1	1.4		2.0
	Asexual	14.7	8.6	8.2		10.0	11.2	6.6	4.5		6.9
	Other	1.1	0.7	0.5		0.7	0.4	0.6	0.2		0.3
Occupational status	Full-time	43.7	35.0	32.5	<.0001	36.2	53.1	76.9	80.8	<.0001	72.3
	Part-time	18.9	27.0	28.2		25.4	11.0	7.6	4.2		7.1
	Self-employed	2.7	4.2	4.6		4.0	3.1	5.9	8.7		6.3
	Student	17.4	0.0	0.0		4.6	19.6	0.1	0.0		5.2
	Housewife/husband	8.0	26.9	28.8		22.7	0.3	1.0	0.8		0.7
	Unemployed	9.3	6.9	6.0		7.1	12.9	8.6	5.6		8.4
Income	<100	38.3	40.8	45.1	<.0001	41.9	35.6	10.8	7.7	<.0001	16.0
(in ¥10,000s)	100–299	35.7	29.8	29.0		31.0	26.1	16.7	12.1		17.2
	300–499	19.9	18.8	15.4		17.6	27.7	35.2	30.4		31.2
	500–799	4.2	7.3	7.3		6.5	8.5	29.7	32.4		25.2
	>800	2.0	3.3	3.2		2.9	2.2	7.6	17.4		10.3
Education	High school or less	32.0	29.2	28.1	<.0001	29.5	30.6	27.4	24.8	<.0001	27.2
	Trade/vocational school or short college	19.0	27.5	36.4		29.0	11.2	15.5	15.9		14.5
	Undergraduate studies	47.5	40.6	33.1		39.3	52.2	50.4	47.3		49.6
	Graduate studies	1.5	2.7	2.4		2.3	6.0	6.7	12.0		8.7
Region of residence	Hokkaido & Tohoku	9.7	10.7	10.6	.9903	10.4	10.1	10.7	10.7	.9996	10.5
	Kanto	37.4	35.9	35.5		36.1	37.1	36.3	36.2		36.5
	Chubu	16.1	16.2	16.6		16.4	17.1	17.2	17.3		17.2
	Kansai	18.3	17.3	18.0		17.8	17.5	16.6	17.1		17.0
	Chugoku & Shikoku	7.8	8.2	8.4		8.2	7.9	8.3	8.4		8.2
	Kyushu & Okinawa	10.8	11.7	10.9		11.1	10.3	11.1	10.4		10.6
Urbanity of residence	Within Tokyo’s 23 wards or prefectural capital	30.1	29.6	31.6	.0699	30.6	31.9	30.1	31.4	.0531	31.1
	In Tokyo but outside of the 23 wards	4.5	4.2	3.8		4.1	4.0	5.4	4.3		4.6
	Cities other than prefectural capitals (population >500,000)	15.5	14.6	14.8		14.9	14.3	13.3	12.7		13.3
	Cities other than prefectural capitals (population 300,000–499,999)	15.1	13.1	13.2		13.7	13.3	12.3	11.0		12.0
	Cities other than prefectural capitals (population <300,000)	22.4	27.5	27.5		26.2	25.7	27.9	31.8		28.9
	Village or town	12.4	11.2	9.1		10.6	10.8	11.1	8.8		10.1
Height	Mean (SD)	158.0 (7.3)	158.2 (6.3)	158.4 (5.1)	.4274	158.2 (6.1)	170.3 (8.5)	170.7 (7.0)	171.3 (5.9)	.0044	170.8 (6.9)
Weight	Mean (SD)	50.6 (10.1)	51.8 (9.4)	52.7 (8.6)	<0.0001	51.8 (9.4)	63.4 (14.8)	65.8 (12.2)	68.9 (11.1)	<0.0001	66.5 (12.6)
How would you describe your attractiveness?	Above average	9.5	9.3	8.6	.0607	9.0	9.8	8.6	8.9	.6593	9.0
	About average	53.9	54.8	59.4		56.5	53.4	55.9	56.3		55.4
	Below average	36.6	35.9	32.0		34.4	36.8	35.5	34.8		35.5

Table 2. Weighted proportions of female NInJaS respondents reporting certain sexual behaviors, stratified by sex and ten-year age groups.

		20–29 (N = 1333)	30–39 (N = 1333)	40–49 (N = 1334)	p	20–49 (N = 4000)
With whom have you had sexual experiences so far?	Only with the opposite sex; never with the same sex	64.6	81.0	87.1	<.0001	79.3
	Mostly with the opposite sex; occasionally with the same sex	5.0	3.4	2.5		3.5
	Both with the opposite and same sexes in roughly equal amounts	1.6	1.0	0.9		1.1
	Mostly with the same sex; occasionally with the opposite sex	0.7	0.3	0.5		0.5
	Only with the same sex; never with the opposite sex	1.2	0.8	0.8		0.9
	I have never had any sexual experiences	26.9	13.5	8.2		14.8
Have you ever had sexual partners (vaginal sex, anal sex, and/or oral sex only)?	No	29.7	14.0	7.3		15.3
	Yes	70.3	86.0	92.7		84.7
Number of lifetime sexual partners (including CSW)	0	29.7	14.0	7.3	<.0001	15.3
	1	20.5	17.2	16.7		17.9
	2	10.3	11.2	13.1		11.8
	3–4	15.2	19.7	18.7		18.1
	5–9	11.0	18.7	21.8		18.0
	10 or more	13.2	19.3	22.4		19.0
Number of lifetime sexual partners (including CSW) [median (IQR)]		1 (0–4)	3 (1–6)	4 (2–8)		3 (1–6)
Number of lifetime sexual partners (excluding CSW)	0	31.7	15.7	8.2	<.0001	16.8
	1	20.4	17.2	16.9		17.9
	2	10.3	11.2	12.9		11.6
	3–4	14.7	19.2	18.6		17.8
	5–9	10.5	19.3	22.8		18.5
	10 or more	12.4	17.5	20.6		17.5
Number of lifetime sexual partners (excluding CSW) [median (IQR)]		1 (0–4)	3 (1–6)	4 (1–7)		3 (1–6)
Age at first volitional sexual intercourse [median (IQR)]		20 (18-)*	20 (17–24)	20 (18–22)		20 (18–24)
First sexual intercourse before age 16 years		9.7	9.2	6.2	.0018	8.0
Number of sexual partners in past year (including CSW)	0	41.7	39.7	51.7	<.0001	45.3
	1	45.2	52.6	43.8		46.9
	2 or more	13.1	7.8	4.6		7.8
Number of sexual partners in past year (including CSW) [median (IQR)]		1 (0–1)	1 (0–1)	0 (0–1)		1 (0–1)
Number of sexual partners in past year (excluding CSW)	0	42.6	41.1	52.5	<.0001	46.3
	1	45.4	52.8	44.2		47.2
	2 or more	12.0	6.1	3.3		6.5
Number of sexual partners in past year (excluding CSW) [median (IQR)]		1 (0–1)	1 (0–1)	0 (0–1)		1 (0–1)
Sexual intercourse frequency in past year (including CSW)	Daily or almost daily	1.0	1.1	0.5	<.0001	0.8
	3–5 times per week	4.9	1.9	1.0		2.3
	1–2 times per week	13.8	10.9	6.6		9.9
	2–3 times per month	17.4	17.6	11.4		15.0
	Once per month or less	21.2	28.9	28.8		26.8
	Never	41.7	39.7	51.7		45.3
Sexual intercourse frequency in past year (excluding CSW)	Daily or almost daily	0.8	0.6	0.3	<.0001	0.5
	3–5 times per week	4.1	2.2	1.0		2.2
	1–2 times per week	13.2	10.3	6.5		9.5
	2–3 times per month	17.7	17.5	11.4		14.9
	Once per month or less	21.7	28.4	28.3		26.6
	Never	42.6	41.1	52.5		46.3
Masturbation frequency	Daily or almost daily	3.0	2.1	0.9	<.0001	1.8
	3–5 times per week	4.7	3.7	2.7		3.5
	1–2 times per week	14.4	11.6	6.7		10.2
	2–3 times per month	11.7	14.1	10.2		11.8
	Once per month or less	13.8	20.1	25.3		20.6
	Never or almost never	52.4	48.4	54.3		51.9
Pornography viewing frequency	Daily or almost daily	2.1	2.0	0.7	<.0001	1.5
	3–5 times per week	4.3	2.3	1.3		2.4
	1–2 times per week	10.1	7.0	2.8		6.1
	2–3 times per month	10.2	9.0	5.5		7.8
	Once per month or less	17.5	19.1	17.0		17.8
	Never or almost never	55.8	60.6	72.8		64.5
Does your pornography viewing (or your partner’s) exert an effect on your sex life?	No effect	29.7	26.8	20.5	<.0001	24.9
	Good effect	11.7	11.2	7.1		9.6
	Bad effect	3.8	2.6	1.8		2.6
	Unsure	30.9	37.1	40.1		36.7
	Neither I nor my partner use pornography	24.0	22.3	30.5		26.2
“I am satisfied with my sex life”	Strongly agree	7.4	7.6	6.1	.0001	6.9
	Agree	25.9	20.1	18.5		20.9
	Neither agree nor disagree	51.5	52.9	57.8		54.6
	Disagree	8.9	10.5	11.0		10.3
	Strongly disagree	6.4	9.0	6.6		7.3
Would you like to change your frequency of sexual intercourse?	Yes, I would like to increase it a lot	6.0	6.5	4.6	<.0001	5.6
	Yes, I would like to increase it a little	24.3	21.9	17.0		20.5
	No	58.3	56.6	65.1		60.6
	Yes, I would like to decrease it a little	3.7	5.4	3.4		4.1
	Yes, I would like to decrease it a lot	7.8	9.7	9.9		9.3
How important is sex to you?	Very important	10.8	10.2	6.8	<.0001	8.9
	Somewhat important	32.4	31.2	23.9		28.5
	Neither important nor unimportant	28.0	26.2	31.3		28.8
	Not very important	15.3	14.6	19.7		16.9
	Not important at all	13.5	17.8	18.3		16.9
Have you ever used CSWs?	No	94.7	95.6	97.2	.0054	96.0
	Yes	5.3	4.4	2.8		4.0
Have you ever used/received:**
Soapland (soopu)		1.4	2.0	1.1	.1516	1.5
Erotic massage (seikan massaaji)		1.3	1.3	0.7	.2309	1.0
Call services (fasshon herusu/deribarii herusu)		1.1	1.9	1.2	.184	1.4
Image club (imeeji kurabu)		1.0	1.1	0.4	.0765	0.8
Pink salon (pinku saron)		1.0	1.1	0.6	.2905	0.8
Male sex worker (urisen)		0.6	0.7	0.3	.269	0.5
Sexy cabaret (sekushii kyabakura)		1.1	1.4	0.3	.0085	0.8
Other		0.3	0.5	0.6	.5835	0.5
Yes, but unsure of what type of establishment		0.5	0.3	0.4	.8986	0.4
Never used CSW		94.7	95.6	97.2	.0054	96.0

*No 75^th percentile is presented as less than 75% of those in the 20–29 years category have had sexual intercourse.

**Soaplands refer to a commercial sex establishment that offers erotic massages using personal lubricant often paired with penetrative intercourse. Call services are split into two types: “fashion health” refers to commercial sex work establishments that typically offer erotic massages and oral sex, but penetrative intercourse may incur an extra charge; “delivery health” refers to a service in which commercial sex workers meet clients at their homes or hotels and offer the same services as “fashion health.” Image clubs are commercial sex establishments in which staff dress in costumes (e.g., schoolgirls or nurses). Pink salons are commercial sex establishments that primarily offer oral sex. Urisen generally refers to male sex workers who primarily cater to homosexual men. Sexy cabaret are hostess clubs (e.g., bars with female staff that cater to men) where sexual conduct may be included among their services.

Table 3. Weighted proportions of male NInJaS respondents reporting certain sexual behaviors, stratified by sex and ten-year age groups.

		20–29 (N = 1333)	30–39 (N = 1333)	40–49 (N = 1334)	p	20–49 (N = 4000)
With whom have you had sexual experiences so far?	Only with the opposite sex; never with the same sex	54.9	76.7	86.9	<.0001	75.2
	Mostly with the opposite sex; occasionally with the same sex	2.4	1.6	2.4		2.1
	Both with the opposite and same sexes in roughly equal amounts	1.6	1.2	0.5		1.0
	Mostly with the same sex; occasionally with the opposite sex	1.2	0.9	0.7		0.9
	Only with the same sex; never with the opposite sex	1.4	1.4	0.8		1.1
	I have never had any sexual experiences	38.5	18.2	8.9		19.6
Have you ever had sexual partners (vaginal sex, anal sex, and/or oral sex only)?	No	43.0	17.1	7.4		19.8
	Yes	57.0	82.9	92.6		80.2
Number of lifetime sexual partners (including CSW)	0	43.0	17.1	7.4	<.0001	19.8
	1	14.3	10.7	11.3		11.9
	2	7.2	9.0	7.2		7.8
	3–4	9.2	11.6	12.5		11.3
	5–9	11.5	17.0	16.5		15.3
	10 or more	14.9	34.7	45.3		33.9
Number of lifetime sexual partners (including CSW) [median (IQR)]		1 (0–5)	5 (1–10)	6 (2–20)		4 (1–10)
Number of lifetime sexual partners (excluding CSW)	0	46.9	19.8	9.2	<.0001	22.5
	1	15.7	15.3	14.5		15.1
	2	8.5	11.0	11.2		10.4
	3–4	9.1	14.6	17.0		14.2
	5–9	9.3	18.9	19.9		16.8
	10 or more	10.6	20.6	28.1		21.1
Number of lifetime sexual partners (excluding CSW) [median (IQR)]		1 (0–3)	3 (1–6)	4 (2–10)		3 (1–6)
Age at first volitional sexual intercourse [median (IQR)]		22 (18-)*	20 (17–26)	20 (18–23)		20 (18–27)
First sexual intercourse before age 16 years		7.9	11.3	6.4	.0001	8.4
Number of sexual partners in past year (including CSW)	0	55.1	39.2	41.8	<.0001	44.5
	1	27.3	43.0	42.0		38.4
	2 or more	17.7	17.8	16.2		17.1
Number of sexual partners in past year (including CSW) [median (IQR)]		0 (0–1)	1 (0–1)	1 (0–1)		1 (0–1)
Number of sexual partners in past year (excluding CSW)	0	57.9	43.2	46.1	<.0001	48.3
	1	28.8	44.7	43.7		40.1
	2 or more	13.3	12.1	10.2		11.6
Number of sexual partners in past year (excluding CSW) [median (IQR)]		0 (0–1)	1 (0–1)	1 (0–1)		1 (0–1)
Sexual intercourse frequency in past year (including CSW)	Daily or almost daily	2.8	1.4	0.8	<.0001	1.5
	3–5 times per week	3.7	3.4	1.1		2.5
	1–2 times per week	9.5	11.5	7.3		9.2
	2–3 times per month	11.1	14.5	15.4		14.0
	Once per month or less	17.9	30.0	33.6		28.3
	Never	55.1	39.2	41.8		44.5
Sexual intercourse frequency in past year (excluding CSW)	Daily or almost daily	2.0	1.0	0.8	<.0001	1.2
	3–5 times per week	3.3	3.5	1.1		2.4
	1–2 times per week	10.0	11.2	7.0		9.1
	2–3 times per month	11.2	14.0	14.9		13.6
	Once per month or less	15.6	27.1	30.1		25.3
	Never	57.9	43.2	46.1		48.3
Masturbation frequency	Daily or almost daily	19.5	13.4	8.8	<.0001	13.0
	3–5 times per week	22.0	21.0	18.4		20.2
	1–2 times per week	25.5	35.4	36.8		33.3
	2–3 times per month	6.6	10.7	16.5		12.1
	Once per month or less	7.3	8.8	11.8		9.7
	Never or almost never	19.2	10.8	7.7		11.7
Pornography viewing frequency	Daily or almost daily	15.1	11.8	7.8	<.0001	11.0
	3–5 times per week	19.7	18.9	17.3		18.4
	1–2 times per week	24.2	30.7	33.0		30.0
	2–3 times per month	8.0	12.0	14.9		12.2
	Once per month or less	9.6	11.1	15.6		12.6
	Never or almost never	23.4	15.5	11.5		15.9
Does your pornography viewing (or your partner’s) exert an effect on your sex life?	No effect	34.5	33.7	36.7	<.0001	35.2
	Good effect	18.5	20.2	19.1		19.3
	Bad effect	5.5	4.9	2.6		4.1
	Unsure	26.9	31.8	34.3		31.5
	Neither I nor my partner use pornography	14.8	9.4	7.3		9.9
“I am satisfied with my sex life”	Strongly agree	6.8	5.1	3.0	<.0001	4.7
	Agree	20.7	20.0	15.9		18.5
	Neither agree nor disagree	48.8	47.8	51.8		49.8
	Disagree	13.4	14.7	15.8		14.8
	Strongly disagree	10.2	12.5	13.4		12.3
Would you like to change your frequency of sexual intercourse?	Yes, I would like to increase it a lot	16.1	17.2	19.2	.0001	17.7
	Yes, I would like to increase it a little	26.6	28.4	30.1		28.6
	No	48.8	47.7	47.3		47.8
	Yes, I would like to decrease it a little	2.4	2.3	1.0		1.8
	Yes, I would like to decrease it a lot	6.1	4.5	2.5		4.1
How important is sex to you?	Very important	16.1	18.8	19.5	<.0001	18.4
	Somewhat important	30.1	37.4	38.3		35.9
	Neither important nor unimportant	33.9	28.3	28.1		29.7
	Not very important	8.9	8.0	9.4		8.9
	Not important at all	11.0	7.5	4.7		7.2
Have you ever used CSWs?	No	71.4	50.3	40.4	<.0001	51.7
	Yes	28.6	49.7	59.6		48.3
Have you ever used/received:**
Soapland (soopu)		16.2	32.0	38.5	<.0001	30.6
Erotic massage (seikan massaaji)		5.5	13.0	17.5	<.0001	12.9
Call services (fasshon herusu/deribarii herusu)		12.5	27.9	35.6	<.0001	27.1
Image club (imeeji kurabu)		2.1	5.0	9.3	<.0001	6.0
Pink salon (pinku saron)		8.3	20.2	26.0	<.0001	19.5
Male sex worker (urisen)		1.3	2.2	3.2	.0146	2.4
Sexy cabaret (sekushii kyabakura)		5.7	17.8	19.3	<.0001	15.2
Other		1.6	2.8	2.7	.1401	2.5
Yes, but unsure of what type of establishment		1.2	1.5	2.6	.0462	1.9
Never used CSW		71.4	50.3	40.4	<.0001	51.7

*No 75th percentile is presented as less than 75% of those in the 20–29 years category have had sexual intercourse.

**Soaplands refer to a commercial sex establishment that offers erotic massages using personal lubricant often paired with penetrative intercourse. Call services are split into two types: “fashion health” refers to commercial sex work establishments that typically offer erotic massages and oral sex, but penetrative intercourse may incur an extra charge; “delivery health” refers to a service in which commercial sex workers meet clients at their homes or hotels and offer the same services as “fashion health.” Image clubs are commercial sex establishments in which staff dress in costumes (e.g., schoolgirls or nurses). Pink salons are commercial sex establishments that primarily offer oral sex. Urisen generally refers to male sex workers who primarily cater to homosexual men. Sexy cabaret are hostess clubs (e.g., bars with female staff that cater to men) where sexual conduct may be included among their services.