Researchers develop and test a diary app that encourages positive reflections on daily work

Work engagement is a persistent, positive state of mind that enhances productivity, creativity, and well-being. However, few practical methods exist to foster it. Addressing this gap, researchers from Japan developed WEDiary, a smartphone app that encourages daily positive reflection on work achievements. In a randomized controlled trial involving 600 Japanese workers, the app significantly improved work engagement levels in only 2 weeks, with effects lasting 3 weeks beyond the intervention.

Work engagement is a positive and persistent state of mind related to one’s work. It is characterized by high energy and mental resilience (vigor), enthusiasm and involvement (dedication), and complete concentration in the task at hand (absorption). Engaged workers are not merely more productive; they are more likely to be proactive, creative, and less susceptible to burnout. Most importantly, work engagement has been consistently linked to many health benefits and overall well-being.

Despite its relevance for both organizations and workers alike, there aren’t many scientifically proven strategies for improving work engagement. Simple methods—ones that can be easily adopted in daily life—are virtually nonexistent. For countries like Japan, where long working hours and work-related mental health issues are common, there is a pressing need to develop tools to help employees feel positive about their job.

Against this backdrop, a research team led by Professor Akihito Shimazu from Keio University, Japan, developed a practical solution. In their latest paper, published in the Volume 13 of the journal JMIR mHealth and uHealth, on September 25, 2025, the team presents a new app called WEDiary, a smartphone-based diary that promotes positive reflections in daily working life on work engagement. The study was authored by Mr. Masahito Tokita and co-authored by Professor Akihito Shimazu, Mr. Shuichiro Kobayashi, and Mr. Daisuke Miyanaka from Keio University; Mr. Nobuyuki Takate and Mr. Hiroyuki Nakano from Japan Productivity Center; and Mr. Kazuki Takeuchi from Labor Trust LCC.

To test their app, the team conducted a randomized controlled trial involving 600 Japanese workers, who were split evenly between an intervention group and a control group. Participants in the intervention group used WEDiary for 2 weeks. They had to set a weekly goal at the beginning of each week and fill in their work achievements at the end of each day. The app specifically prompted them to type in their successes rather than any shortcomings, promoting positive reflection. “Through consistent engagement with this reflective practice, we expected participants to cultivate and accumulate positive emotions over time,” explains Mr. Tokita, “The transient experience of isolated positive emotions alone is insufficient for resource building toward work engagement. Instead, sustained accumulation of such emotions is essential, which is the goal of WEDiary.”

Through follow-up surveys, the team evaluated the effectiveness of their approach, obtaining very promising results. “Our app significantly improved employees’ work engagement in terms of vigor and dedication. Notably, these improvements were observed after just 2 weeks of intervention and persisted for 3 weeks post-intervention,” highlights Mr. Tokita. These findings showcase the potential of a simple, self-guided tool to effectively support workers’ psychological well-being by fostering work engagement.

A key advantage of WEDiary is its ease of use and adoption. It can be seamlessly incorporated into corporate wellness programs as a tool for mental health support. Similarly, it may be equally effective in remote and flexible working contexts, supporting self-management and engagement outside of traditional office settings. “Given its low cost and scalability, WEDiary could benefit a wide range of organizations, including small- and medium-sized enterprises and the public sector,” concludes Prof. Shimazu, “Ultimately, it addresses pressing challenges in Japanese society, such as long working hours and mental health issues, while fostering sustainable engagement in the workplace.”

Further innovations in tools that increase work engagement will hopefully pave the way for a healthier society.

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Reference
Title of original paper: Effects of a Smartphone-Based Positive Reflection Diary on Work Engagement Among Japanese Workers: A Randomized Controlled Trial
Journal: JMIR mHealth and uHealth
DOI: 10.2196/55664

About Keio University Global Research Institute (KGRI), Japan
The Keio University Global Research Institute (KGRI) was established in November 2016 as a research organization to bridge faculties and graduate schools across the university. KGRI aims to promote interdisciplinary and international collaborative research that goes beyond the boundaries of singular academic disciplines and international borders. It also aims to share research outcomes both in Japan and worldwide, further promoting engagement in joint research. To enhance those activities above, in 2022, Keio University set its goal of becoming a “Research university that forges the common sense of the future”.

Website: https://www.kgri.keio.ac.jp/en/index.html

About Professor Akihito Shimazu from Keio University
Akihito Shimazu is Professor of the Faculty of Policy Management at Keio University. He is qualified as a clinical psychologist and a national licensed psychologist in Japan. His research concerns workplace psychosocial factors and mental health. He has published 11 edited books and over 300 papers/book chapters.
https://en.hp3.jp/
https://researchmap.jp/read0058233?lang=en

About Senior Researcher Masahito Tokita from Keio University SFC
Masahito Tokita is a Senior Researcher at Keio University SFC (Keio Research Institute at SFC: KRIS). He is a national licensed nurse and a national licensed mental health social worker in Japan. His research concerns workers’ well-being and mental health.

Funding information
This research was funded by a grant from the Japan Productivity Center.