Objective: Mental health issues among employees cause significant productivity losses through presenteeism and absenteeism. This study aimed to quantify productivity losses caused by employees with mental health issues in Japan. Methods: Participants were recruited to match the Japanese population distribution by gender, age, and region. Mental health status and productivity loss were assessed using self-administered questionnaires. The results were extrapolated to estimate nationwide impact calculated using probabilistic sensitivity analysis. Results: We analyzed 27,507 individuals. Productivity loss due to mental health–related presenteeism was estimated at $46.73 billion, and absenteeism at $1.85 billion, equivalent to 1.1% of Japan’s GDP and over seven times the medical costs for mental disorders. Women in their 20s reported more mental health issues than men. Conclusions: These results highlight the urgent need for businesses and governments to enhance workplace mental health measures.

Introduction Many developed countries including Japan are experiencing declining birth rates, particularly in urban areas. A gap between the planned number of children and the actual number of children exists, that is attributed to various factors such as: childcare leave and employment policies, childcare services, financial support, husbands’ contributions to household chores and childcare, marriage support, community, and couples’ well-being. Therefore, we propose HAMA study for having a baby, parenting, and marriage life (HAMA = ‘H’aving ‘A’ baby, parenting, and ‘MA’rriage life) in Yokohama (an urban area) to examine these issues. Methods and analysis In this large-scale cohort study, we will elucidate the actual situation of families and child-rearing in Yokohama, evaluate the current policies and propose future measures to prevent a decline in the birth rate. Overall, 10 000 young married couples (wives aged 20–39 years as of 2022) will be randomly selected, and a survey form will be sent to them annually. They will be followed-up for 5 years to examine the factors associated with the planned number of children, well-being of the couple, childcare support policies, externalisation of housework and childcare, fathers’ participation in housework and childcare, wives’ free time, loneliness and social connectedness, relationship with the spouse and if they are working, questions regarding their work style and work-life balance will also be included. Ultimately, a conceptual model of the planned number of children and associated factors will be developed. Ethics and dissemination This study has been approved by the Ethics Committee of Yokohama City University (reference number: 2022–10) and will be conducted following appropriate ethical guidelines. Opportunities to withdraw consent to participate in the survey are provided to participants. The results of this survey will be published as research papers in relevant journals and will be reported to the administration of Yokohama city and other agencies.

In Japan, where the shortage of care workers poses a challenge to the sustainability of the long-term care system, foreign care workers play a crucial role. This study aimed to identify the needs and challenges of Vietnamese Technical Intern Training candidates, the largest group of foreign care workers, to facilitate program reforms and a more efficient recruitment process. A semi-structured interview survey was conducted with 27 candidates in Vietnam. Interview items included reasons for choosing the training program in Japan, the desired length of stay, expectations, and career advancement after returning home. Descriptive statistics and K-means clustering were used to analyze the data. Survey results showed that all participants independently decided to pursue care worker training in Japan; 44% had considered other countries; most wanted to stay in Japan for as long as possible; and 37% wanted to live in Japan permanently. The K-means method revealed three clusters: a Japanophile cluster (preferred Japan for its landscape, culture, and national character); a word-of-mouth cluster (influenced by personal referrals); and an intellectual cluster (influenced by Japan’s economic development and care levels). Our findings indicate that support for obtaining qualifications, Japanese language skills, and caregiving skills are important to secure the stability of foreign care workers. It is necessary to tailor recruitment, training, and support for each cluster.

Purpose: This study examines the Food for Specified Health Uses (FOSHU) system in Japan, which features a unique certification logo (FOSHU seal) not present in other functional food systems and whose influence on consumer purchase intention remains unclear. Specifically, it aims to (1) examine the FOSHU seal’s influence on consumer purchase intention, (2) compare the effects of the FOSHU seal and health claims and (3) assess the impact of consumers’ perception of FOSHU, their FOSHU purchasing experience, and the perception of their gastrointestinal condition. Design/methodology/approach: Data were collected from Japanese respondents through a questionnaire survey using conjoint measurements. Ordered multinomial logistic regression analysis was employed, with FOSHU seal, health claims, sugar-free and extra quantity labels as independent variables and ordered purchase intention as the dependent variable. Findings: The results indicated that the FOSHU seal on functional food products positively influences consumer purchase intention, with health claims exerting a greater influence than the FOSHU seal. Additionally, purchase intention is positively affected when consumers perceive the FOSHU seal as a mark of authenticity. Originality/value: This study is novel in two respects. First, it extends brand research, which has traditionally focussed on corporate and product brands, to certification marks, demonstrating their effect on purchase intention. Second, creating similar logos for functional foods beyond those for specified health uses in Japan or in similar systems in other countries could improve purchase intentions.

BACKGROUND University withdrawal carries disproportionately severe and lasting consequences in Japan, where those who leave higher education face long-term labor-market disadvantage despite a comparatively low dropout rate. A substantial share of withdrawals reflect maladjustment, low motivation, and disengagement rather than academic or financial causes alone, pointing to a weak sense of belonging as a common substrate. Sense of belonging is a well-established correlate of adjustment and persistence, yet the evidence remains largely cross-sectional, and interventions typically reach only students who already participate—leaving the disengaged, who are most at risk, structurally absent from both support and evidence. OBJECTIVE This trial tests whether encouraging disengaged first-year students to visit a permanent on-campus “belonging café” improves their sense of belonging. The primary hypothesis is that students randomized to encouragement show greater improvement in belonging over time than control students. METHODS In this single-site, parallel-group randomized controlled trial with five measurement waves, first-year students who were not using the café (non-users) are randomized 1:1 to an encouragement group or a control group, using stratified block randomization by faculty; existing users are followed as a non-randomized reference cohort. The encouragement is delivered through LINE, the messaging platform students most reliably use, with the two groups differing only in the LINE account to which they are invited. The primary outcome is sense of belonging (PSSM-13J), measured at every wave; secondary outcomes are well-being (WHO-5), loneliness, and intention to withdraw, with café visits as the hypothesized mediator. The primary analysis is a linear mixed-effects model testing the group-by-time interaction under an intention-to-treat framework, emphasizing effect size with 95% confidence interval. The trial is powered to detect an effect of approximately d = 0.4. RESULTS The trial was registered on the Open Science Framework prior to any outcome analysis. Recruitment and baseline assessment were completed in June 2026, with follow-up assessments scheduled through January 2027. As of submission, data collection is ongoing and no outcome analysis has been conducted. [IRRID: to be assigned on publication.] CONCLUSIONS By combining a randomized design, prospective measurement, and a delivery channel chosen for its reach, this trial aims to provide causal evidence on a preventive, environment-level approach to student belonging, and to extend attention from the anxious-but-present to the disengaged. The protocol offers a model for rigorous causal evaluation of measures intended to address young people’s difficulties. CLINICALTRIAL UMIN Clinical Trials Registry UMIN000061938; https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000070843. The trial was registered retrospectively (18 June 2026); the analysis plan was pre-registered on the Open Science Framework prior to any outcome analysis (osf.io/qt5bm).

Background Foreign caregivers are assuming increasing importance in Japan due to a significant shortage of caregivers. To secure and train stable human resources, it is important to understand the needs and challenges of foreign caregivers. Objective To identify the needs and challenges of Vietnamese technical interns, the largest group of foreign caregivers in Japan, to facilitate system reforms for foreign caregivers and a more efficient recruitment process. Methods A semi-structured interview survey was conducted with 27 Vietnamese technical interns (caregivers). Interview items included reasons for choosing technical internship in Japan, desired length of stay, and expectations in Japan, as well as career advancement after returning home. Descriptive statistics and k-means clustering were used to analyze the data. Results Survey results showed that all respondents had made their own decision to come to Japan and wanted to pursue caregiver certification; 44% had also considered other countries apart from Japan; most wanted to stay in Japan for as long as possible; 37% wanted to live in Japan permanently. The k-means method revealed three clusters: Japanophile cluster or those who preferred Japan for its landscape, culture, and national character; Word-of-mouth cluster or those influenced by personal referrals; and Intellectual cluster or those influenced by Japan’s economic development and care levels. Conclusions Vietnamese technical interns hoped to study advanced Japanese, become certified care workers, and work in the nursing field after returning to their home country. They also tended to want to stay in Japan for a longer period than that assumed for technical internship programs. Our findings indicate that support for obtaining qualifications, Japanese language skills, and caregiving skills are important to secure stable foreign caregivers. Since each cluster had different backgrounds and reasons, motives, and assumptions for coming to Japan, it is necessary to tailor recruitment, training, and support for each cluster.