The Yucho Passbook App, offered by Japan Post Bank, is a service where FOURDIGIT has long played a role as a design partner, always valuing the user’s perspective. To deepen the understanding of service design, a hands-on training session was recently held. Young members from both Japan Post Bank and FOURDIGIT teamed up to experience an actual service design process, creating a valuable opportunity to learn together.

This article shares the journey from the planning and implementation of the training to the insights and changes it brought about, told through the voices of the project members. What kind of realizations and learnings emerged from this practical project? Furthermore, how did the training influence the team and their relationships? By retracing their steps, we explore insights into how service design can be practically applied in the workplace.

Suenari:
We’ve been working with Japan Post Bank since the development of the Yucho Passbook App, released in February 2020. Through adding features and making improvements, we’ve shared design philosophies through actual initiatives and built a long-term partnership. We had been discussing how we wanted them to understand FOURDIGIT’s design approach, and for the team to continue thinking with that DNA as it’s passed on.

In that context, when we introduced FOURDIGIT’s design training programs, it coincided with new members joining the “Passbook App” team. They consulted with us, hoping the entire team could become more proactive in thinking about the app. That’s when we proposed this training.

Nanaumi:
We’ve been seeing an increase in younger members on our team. While we also have experienced staff, there’s no guarantee the same people will continue working on the project in the future. Amidst that, we believed that if we could establish “user-centered service development” as a shared foundation, we could maintain the team’s direction. Even if members change, this “user perspective” axis is akin to what Suenari-san calls “DNA,” and it’s something we believe should be inherited as an organization. We are truly grateful that this training became a reality.

Nitta:
For this training, I was in charge of the on-site facilitation, and Suenari reviewed the deliverables. With support from another FOURDIGIT executive officer, five members from Japan Post Bank, including Takayama-san and Tahara-san, and two members from FOURDIGIT participated as trainees.
Takayama-san and Tahara-san, how did you come to join the training?

Takayama:
From my first year at the company, I was assigned to headquarters, working simultaneously in the research and analytics team as well as the team responsible for advertising the “Passbook App.” In my second year, I received information about this training and, encouraged by my manager’s recommendation, I volunteered, thinking, “This sounds interesting.”

Tahara:
This is my first year in this department. Before this, I was involved in customer-facing roles at a Japan Post Bank branch. When I became responsible for the “Passbook App” development, I frequently heard the phrase “think from the user’s perspective.” However, I felt I was thinking from a biased viewpoint, focusing on certain demographics, and lacked the foundation to practice the “user perspective” in its true sense. Learning that mindset and process thoroughly through this training was a very valuable experience.

Nitta:
The two participants from FOURDIGIT were also new; one had just joined, and the other was a second-year graduate. Therefore, all trainees started from roughly the same stage, creating an ideal team structure where they could learn from and inspire each other. It was an extremely meaningful opportunity to grow together through practice at a time when they were about to acquire the design process approach.

Suenari:
This training involved learning the service design process in a hands-on format, using the Yucho Passbook App as the subject. We worked towards the goal of “envisioning the future of the Passbook App” through brainstorming, persona design, and user research. Are there any moments that left a strong impression?

Takayama:
Definitely the user interviews. Having worked at headquarters since joining the company, it was my first time interacting directly with actual customers. I was so struck by the strong realization that there are “people” behind the numbers that I was almost at a loss for words. It was the moment the data I had been analyzing connected with real experiences.

Suenari:
When you only look at numbers, the user image tends to become abstract, doesn’t it?

Takayama:
Exactly. Especially for someone like me who primarily works with aggregated data, it’s easy to focus on majority trends and demographics. But when you meet them in person, you see each individual’s background and emotions. Realizing that gap was a significant learning experience.

Tahara:
What particularly impressed me was the survey design and analysis. For personas of different ages and genders, we had many questions we wanted to ask, but we had to narrow them down. That selection process was difficult but also a great learning experience. In analyzing the results, we found many commonalities in the services desired by completely different personas. This helped us see the essential aspect of “what the Passbook App should be” and connect it to concrete outputs.

Suenari:
From the design side, it’s easy to think “this and that too,” but you also need to consider the user’s attention span. However, the desire to ask is very important. If you don’t see it as your own concern, the question of “what do I want to ask?” won’t even arise.

Nanaumi:
Data alone only shows macro trends. That’s why I feel it’s important to obtain information with a sense of “granularity” through processes like these. I believe we got closer to the essence because we thought deeply during the question design phase.

Nitta:
I’m truly happy that everyone experienced firsthand what we emphasized at the beginning of the training: “knowing the user is key.” Actually, I personally prefer interviews over brainstorming. I find the process of listening to someone and understanding their situation fascinating. I’m glad if they got to experience that.

Suenari:
Your insights were, in a way, unexpected. Many people tend to find the brainstorming phase the most enjoyable, but the fact that you thoroughly grasped the value of “knowing the customer” is a significant achievement. I believe that while there were things gained through the training, it was the connection with your inherent attitude and daily work that led to this deep understanding. It’s not easy in terms of reproducibility, but I feel a very positive cycle was created this time.

Suenari:
Are there any specific episodes from the user research that particularly resonated with you?

Takayama:
The persona I was in charge of was a housewife living in a regional city. Among those I interviewed, some lived very far from the nearest station or couldn’t manage daily life without a car. Having never lived in such an area, I was surprised by the differences in lifestyle and how they use money. For example, even with the same annual income, some people rent in urban areas, while others in rural areas own homes; their values are completely different. I realized just how much living location can change one’s baseline standard of living.

Suenari:
Indeed, lifestyle and values differ greatly depending on where one was born and raised, and their living environment. But actual users are a collection of such diverse people. More than half of Japan is rural, so it’s important not to view the entire country uniformly but to pay attention to regional differences.

Tahara:
There are also differences in family structure and work styles, and I felt these backgrounds cannot be ignored when creating personas. Conversely, I also think that by clearly defining the target, you can achieve more effective results. Since Japan Post Bank and post offices are nationwide, deciding “where to focus” is difficult. I also feel it’s better to avoid narrowing it down too much. I’ve come to realize anew that aiming for a service “everyone can use” is actually incredibly difficult.

Suenari:
Exactly. There’s value in both aiming for accessibility and making new proposals. If you only respond to immediate needs, you inevitably end up creating something simplistic. What’s important is to deeply understand the essential insights revealed through user research, and instead of merely catering to them, propose something that leads to a better outcome. Creating services by balancing both these aspects is crucial.

Nanaumi:
Japan Post Bank has about 120 million accounts. This means it’s used by almost everyone in Japan. Figuring out the best service to offer in such a context is very difficult. Leaning too much towards a specific persona is risky, and conversely, aiming only for universal appeal can result in a lack of substance. I feel a good sense of balance is necessary.

Suenari:
Precisely. Japan Post Bank has an expected role and a brand image that demands a sense of security. For instance, some services might be forgiven for occasional issues with a “well, these things happen” attitude. But for Japan Post Bank, that would be “unacceptable.” There’s an expected level of quality, and maintaining it is a source of trust. In that sense, the service needs to be broadly and stably accepted.

Nanaumi:
That’s exactly right. As a company, we are very sensitive to system failures, and while such expectations have a positive side, they also bring pressure.

Suenari:
However, take the “Lucky Cat” (Maneki-neko) feature in the Passbook App, for example. It was initially designed with women in their 30s as the persona. But in reality, it has been well-received as a source of comfort by older men as well. At first glance, a cat might seem “for young women,” but its cuteness and the way it “talks” to you are actually heartwarming elements for people of all ages and genders. I think that’s a great example.

If we had decided, “Let’s not use a cat because it’s for everyone,” that warm element might never have been born. Instead, by focusing on a specific persona and crafting it with high quality for that target, it consequently became accepted by a broader audience. So, rather than diluting things, I believe we should clearly define the core target and aim for service design and user communication that ripple outwards to the periphery.

Nanaumi:
I strongly feel that interviews like the ones we conducted this time are incredibly important for that very reason.

Suenari:
Through the training, have you felt any changes in yourself?

Takayama:
I’ve started to voice my opinions more. My contributions clearly increased after this training. Before, I used to hesitate, wondering, “Is it okay to say this?” But through this training, I came to feel that “even if I make a mistake, someone will back me up.” I was able to switch gears and think, “Let’s just try saying it!”

Nanaumi:
Are you able to apply that in your current work?

Takayama:
Yes. Even when discussing the direction for the next fiscal year, I can now clearly express my opinions. From midway through the training, I started to naturally offer opinions, thinking, “Let’s try saying this next,” or “Maybe there’s this angle too.” My way of thinking expanded.

Nitta:
Indeed, conversations increased significantly in the latter half, and during user interviews, your questions became progressively deeper. You moved beyond superficial questions to elicit more essential insights, and I sensed your growth.

Tahara:
I feel I’ve developed the ability to think from the “user’s perspective.” I’m involved in developing new features, and even when designing screens and user flows, I now consciously consider, “Is this difficult for the user to navigate?” or “Am I creating a path to the feature they truly want to use?” Even when creating materials, I find myself thinking, “This part needs more emphasis,” and I feel I’ve developed the habit of thinking from the recipient’s viewpoint.

Nitta:
That’s a wonderful change, isn’t it? Your perspective in daily tasks has shifted, you’re able to state your opinions firmly, and you can make judgments from the user’s point of view.

Nanaumi:
The supervisors of some team members sit in front of me at work, and I’ve noticed that the way members consult with them has changed since the training. The discussions seem to be at a slightly higher level, and I get the impression that conversations proceed on the premise that “I can meet your expectations.”

Suenari:
Whether that premise exists or not significantly changes the quality of communication. Hearing such stories makes me feel that the training has produced tangible results.
Looking back, how do you feel now that the training is over?

Takayama:
Honestly, I strongly feel like I want to see it through to the very end! There’s a sense of “completion,” but I also realize that there’s so much more we can do now. I want to analyze how the ideas we proposed differ from the actual implementation and follow up on that. I hope I can be more involved in such ways in the future.

Tahara:
I feel the same. It was a big realization for me through user research that “the features I wanted to add” and “the features users wanted” were completely different. I want to continue hearing users’ voices directly through interviews and other means.

Nanaumi:
I think the training itself was very thorough. We made considerable progress in persona design and the process of deepening it, and looking at the results of the user acceptance survey, many ideas seemed likely to be well-received by users. There are future challenges, but I feel we’ve made steady progress.

Suenari:
From a business perspective, this training is still just the first step. As you all feel that “what comes next” is important, the real test begins after delivering to the users. In that sense, this initiative was extremely significant. I believe these kinds of training sessions and workshops are, in a way, an effort to increase ambassadors. The fact that everyone involved has come to see the “Passbook App” as their “own concern” (jibun-goto) is a major step forward.

Moreover, the “what comes next” part of connecting this to business results is also crucial in design. Because we’ve had this experience of thinking together through such initiatives, we can naturally move to the next step. And that step doesn’t come from a proposal by us at FOURDIGIT, nor from a request from Japan Post Bank; it arises from a state where we are “one team, and everyone sees it as their own concern.”

Nanaumi:
Exactly. System development sites can easily fall into a client-contractor relationship, a “we do it because we were told to” dynamic. But if we can build a shared understanding and move forward together as we did this time, we can establish a relationship of trust where even if we propose something unconventional, they’ll stop us. I feel that such trust will become increasingly important.

Suenari:
What are your thoughts on the future? Not just the outcome of the training, but also how the “Yucho Passbook App” will grow.

Nanaumi:
For the “Yucho Passbook App,” we have set a target of “25 million registered accounts” by the end of fiscal 2028. We surpassed 13 million accounts as of March 2025, but we anticipate a slowdown at some point, so I believe a more sharply focused approach will be necessary for the next step.

Suenari:
Leveraging the ideas from the training and other initiatives will be key to addressing that challenge. If we can make a significant impact, I believe we can move to the next stage.

Tahara:
While the number of registered accounts is important, it ultimately means nothing if users don’t actually use the app. I believe it’s crucial to maintain active user rates and create an environment where users want to continue using it.

Nanaumi:
Currently, the company has high expectations for the “Passbook App,” even using it in TV commercials. However, cramming too many features into the app could be counterproductive. I think it’s important to identify and provide only the features users truly need.

Nitta:
Through this training, I feel the distance between us and the Japan Post Bank team has significantly shortened. Especially with new members joining, it was a big plus that we could establish a flat and casual relationship at an early stage through the training, something that would normally take time to build. I believe that building a relationship where we can think together from the same perspective will contribute to the future development of the “Passbook App.”

Suenari:
At FOURDIGIT, we value the stance of “not confronting the client, but looking at the same goal together.” I truly feel we were able to build that kind of relationship this time. Furthermore, the fact that we were able to proceed while sharing a user-centered perspective, and that these two aspects have firmly taken root as the team’s baseline, is truly a major step forward. I’m very much looking forward to future developments.

Nanaumi:
I agree. Through this initiative, I feel that the “strength as a team” of the entire project, including FOURDIGIT, has definitely increased. This strong team power is an indispensable element for evolving the “Passbook App” into an even better product, and I hope we will continue to work together as one team to steadily realize the vision of the “future Passbook App” that we derived this time.

Interview and text: Misaki Koyama
Photography: Daishiro Futakami