TOKYO (TR) – IT company Raison d’Etre conducted a survey on marriage and infidelity that targeted married men and women in September.
The results have been revealed — and, perhaps surprisingly, a large number of married persons know about the infidelity of their spouse, reports Otonaanswer.jp (Dec. 13).
The survey was conducted via internet research in September 2025. It randomly selected 480 people (240 men and 240 women) from a total of 6,805 married men and women aged 20-59 (3,305 men and 3,500 women) who had claimed to have “ever cheated.”
One question was, “Has your spouse found out about your affair? Or do they know about it?” The most common answer (45.5 percent) was, “They haven’t suspected it and they haven’t found out.” Coming in second (23.1 percent) was, “They suspect it, but they haven’t found out.”
The spouses of about 20 percent of the respondents have found out. Another 15 percent know about it and accept it, meaning their relationship is open.
Regarding the figure for open relationships, the company commented, “Perhaps relationships become more stable when people allow freedom of multiple partners and sexual desires, based on the idea that it’s impossible to satisfy everything from one person.”
The company then analyzed, “Rather than ignoring or condoning betrayal, believing that it’s better to come to an agreement and make it a rule than to hide it and be betrayed. They may be maintaining an independent marital relationship by not forcibly correcting differences in values and agreeing to eliminate betrayal.”
Looking at the response percentages by gender, about 20 percent of men and 10 percent of women answered “They know about it and it’s public knowledge.” Nearly 20 percent of men and just over 21 of women answered, “They found out.” About 25 percent of men and 21 percent of women answered, “They suspect it but they haven’t found out,” Thirty-five percent of men and about 48 percent of women answered, “They haven’t suspected it and they haven’t found out.”
“Growing support for contract marriages”
The percentages by age group are as follows:
■ They know about it and it’s public knowledge
20s (30.0%), 30s (17.5%), 40s (8.3%), 50s (4.2%)■ They found out
20s (18.3%), 30s (19.2%), 40s (15.0%), 50s (29.2%)■ They suspect it but they haven’t found out
20s (22.5%), 30s (20.0%), 40s (25. 8%), 50s (24.2%)■ They haven’t suspected it and they haven’t found out
20s (29.2%), 30s (43.3%), 40s (50.8%), 50s (42.5%)
Among people in their 20s, 30 percent answered, “They know about it and it’s public knowledge.” While less than 20 percent of people in their 30s gave the same answer. Among people in their 40s and 50s, less than 10 percent gave that answer.
Comparing people in their 20s and 50s, the number of people in their 20s who answered “They know about it and it’s public knowledge” was approximately seven times higher, revealing a significant difference.
The company concluded, “The results suggest that views on love and marriage among people in their 20s and 30s are becoming more diverse, amid progress in non-interference in each other’s private lives, sexual liberalization, and growing support for contract marriages.”
