Increase in Investigation Requests from Men Due to "Joint Custody"
Following the implementation of the joint custody system on April 1, 2026, there has been a sharp increase in infidelity investigation requests from men to investigation companies. With the removal of anxiety about acquiring parental rights, men are increasingly taking the initiative in divorce proceedings, with men accounting for approximately half of the consultations in fiscal year 2025, an increase of about 12% compared to two years prior.
📋 Article Processing Timeline
- 📰 Published: May 12, 2026 at 23:00
- 🔍 Collected: May 12, 2026 at 14:31
- 🤖 AI Analyzed: May 12, 2026 at 15:10 (39 min after Collected)
The joint custody system commenced on April 1, 2026. While it is believed that the option of joint custody will reduce disputes between parents over parental rights during divorce, its impact is also extending to the gender ratio of requests made to investigation companies.
Noriko Itabashi
RCL Co., Ltd.
Deputy Manager, Consultation Department
Certified Counselor, NPO Japan Family Issues Consultation Federation
Industrial Counselor
Joined RCL after working as an English conversation instructor, airport staff, and mental clinic counselor.
Receives over 1000 consultations annually.
Before Enforcement: Many Men Gave Up on Parental Rights
Since the revised law concerning joint custody was enacted on May 17, 2024 (promulgated on May 24), there has been an increasing trend in "requests for infidelity investigations of wives" from men who often gave up, believing it was difficult for fathers to obtain parental rights.
In fiscal year 2023, the ratio was 60% female to 40% male.
However, in 2025...
By fiscal year 2025, approximately half of the clients were men! The number of male consultants increased by about 12% compared to two years ago!
When there was infidelity on the wife's side, many men hesitated to conduct investigations, fearing that taking evidence would anger their wives and prevent them from seeing their children. However, with the option of "joint custody," the anxiety of "not being able to obtain parental rights" disappeared, leading more men to firmly gather evidence of infidelity and seek to take the initiative in "deciding whether or not to divorce."
Has the ability to choose "joint custody" changed men?
Let's introduce some actual consultations.
(※Ages, family structures, etc., have been changed for privacy protection)
Case (1) Mr. A (34, male, civil servant, 3 children)
[Request Details]
Married for 10 years. For the past six months, his wife's outings have increased. Other suspicious behaviors include taking her phone into the bathroom.
He requested an investigation, suspecting his wife might be having an affair by leaving the children at her parents' house when he was on night duty.
[Investigation Results]
His wife met secretly with a high school classmate after leaving the children at her parents' house. Evidence of infidelity was obtained. It was also discovered that she had adulterous relationships with two other men besides this classmate.
[Future Plans?]
He said, "Since I found out she was having affairs with three men, I've decided to divorce. However, I won't bring up divorce until the joint custody system becomes an option! I will absolutely not give up on my children."
Afterward, Mr. A pretended to be calm without confronting his wife, but then stated,
"Since the joint custody system has been enforced, I am currently consulting with a lawyer to claim compensation from both the unfaithful partner and my wife, and simultaneously proceed with divorce discussions."
Case (2) Mr. Y (46, male, company employee, 2 children)
[Request Details]
Married for 14 years. He works remotely and has been actively involved in childcare. However, after changing jobs a year ago, his wife started coming home late, and her outings with friends increased even on holidays, leading him to seek consultation for an investigation. Her underwear became flashy, and she was seen chatting with men on LINE at home, indicating a high possibility of infidelity.
[Investigation Results]
From the beginning of the consultation, Mr. Y said, "I absolutely do not want to give up parental rights. I spend more time with the children than my wife because I work remotely. I want to divorce my wife." As expected, his wife was having an affair with a male colleague, and evidence was obtained.
[Future Plans?]
"I will definitely claim compensation from both my wife and her unfaithful partner. I originally wanted sole custody, but it seems we will settle on joint custody with me taking custody and guardianship. I cannot forgive my wife's infidelity, but as parents of our children, I intend to cooperate with her in the future."
Are Husbands' Positions and Children's Mental Health Protected by Joint Custody?
Under the conventional sole custody system, one parent inevitably lost parental rights upon divorce, which sometimes led to children becoming mentally unstable due to intense parental battles.
With the enforcement of this "joint custody" system, we sincerely hope that the number of people enduring a partner's infidelity for the sake of "parental rights" and children being hurt by parental disputes will decrease.
※About Our Survey
Survey period: May 2023 - April 2024
May 2025 - April 2026
Survey method: Monitor questionnaire
Age group: 10s to 70s
Gender: Male and female
Number of samples collected: 10,393
Noriko Itabashi
RCL Co., Ltd.
Deputy Manager, Consultation Department
Certified Counselor, NPO Japan Family Issues Consultation Federation
Industrial Counselor
Joined RCL after working as an English conversation instructor, airport staff, and mental clinic counselor.
Receives over 1000 consultations annually.
Before Enforcement: Many Men Gave Up on Parental Rights
Since the revised law concerning joint custody was enacted on May 17, 2024 (promulgated on May 24), there has been an increasing trend in "requests for infidelity investigations of wives" from men who often gave up, believing it was difficult for fathers to obtain parental rights.
In fiscal year 2023, the ratio was 60% female to 40% male.
However, in 2025...
By fiscal year 2025, approximately half of the clients were men! The number of male consultants increased by about 12% compared to two years ago!
When there was infidelity on the wife's side, many men hesitated to conduct investigations, fearing that taking evidence would anger their wives and prevent them from seeing their children. However, with the option of "joint custody," the anxiety of "not being able to obtain parental rights" disappeared, leading more men to firmly gather evidence of infidelity and seek to take the initiative in "deciding whether or not to divorce."
Has the ability to choose "joint custody" changed men?
Let's introduce some actual consultations.
(※Ages, family structures, etc., have been changed for privacy protection)
Case (1) Mr. A (34, male, civil servant, 3 children)
[Request Details]
Married for 10 years. For the past six months, his wife's outings have increased. Other suspicious behaviors include taking her phone into the bathroom.
He requested an investigation, suspecting his wife might be having an affair by leaving the children at her parents' house when he was on night duty.
[Investigation Results]
His wife met secretly with a high school classmate after leaving the children at her parents' house. Evidence of infidelity was obtained. It was also discovered that she had adulterous relationships with two other men besides this classmate.
[Future Plans?]
He said, "Since I found out she was having affairs with three men, I've decided to divorce. However, I won't bring up divorce until the joint custody system becomes an option! I will absolutely not give up on my children."
Afterward, Mr. A pretended to be calm without confronting his wife, but then stated,
"Since the joint custody system has been enforced, I am currently consulting with a lawyer to claim compensation from both the unfaithful partner and my wife, and simultaneously proceed with divorce discussions."
Case (2) Mr. Y (46, male, company employee, 2 children)
[Request Details]
Married for 14 years. He works remotely and has been actively involved in childcare. However, after changing jobs a year ago, his wife started coming home late, and her outings with friends increased even on holidays, leading him to seek consultation for an investigation. Her underwear became flashy, and she was seen chatting with men on LINE at home, indicating a high possibility of infidelity.
[Investigation Results]
From the beginning of the consultation, Mr. Y said, "I absolutely do not want to give up parental rights. I spend more time with the children than my wife because I work remotely. I want to divorce my wife." As expected, his wife was having an affair with a male colleague, and evidence was obtained.
[Future Plans?]
"I will definitely claim compensation from both my wife and her unfaithful partner. I originally wanted sole custody, but it seems we will settle on joint custody with me taking custody and guardianship. I cannot forgive my wife's infidelity, but as parents of our children, I intend to cooperate with her in the future."
Are Husbands' Positions and Children's Mental Health Protected by Joint Custody?
Under the conventional sole custody system, one parent inevitably lost parental rights upon divorce, which sometimes led to children becoming mentally unstable due to intense parental battles.
With the enforcement of this "joint custody" system, we sincerely hope that the number of people enduring a partner's infidelity for the sake of "parental rights" and children being hurt by parental disputes will decrease.
※About Our Survey
Survey period: May 2023 - April 2024
May 2025 - April 2026
Survey method: Monitor questionnaire
Age group: 10s to 70s
Gender: Male and female
Number of samples collected: 10,393