Free Headache Diary App 'ZutsuNote' Created by a Practicing Headache Specialist

ZutsuNote, a free headache diary app provided by Iris Wellness Inc. (Shinagawa-ku, Tokyo; CEO: Yuki Maekawa), has surpassed 700 users approximately five months after launch, without running any advertisements.

ZutsuNote was developed by CEO Maekawa, a practicing headache specialist, and its key feature is the statistical analysis of patient-recorded data—including headache symptoms, medication, sleep, and atmospheric pressure—which is directly shared with physicians' examination screens. Developed by a practicing physician with no prior programming experience to solve challenges observed in clinical practice, both user numbers and partnered medical institutions continue to steadily grow.

Why Did a Doctor Decide to Build the App Themselves?

Headache treatment relies on a tool called a 'headache diary,' where patients record their daily symptoms. This is an essential record forming the foundation of diagnosis and treatment, recommended by international guidelines. However, paper-based diaries remain the norm. CEO Maekawa launched an online headache clinic to reduce the burden on patients traveling from distant areas, but encountered a major obstacle: during online consultations, paper diaries can only be viewed through a screen, leading to time-consuming interactions like 'Tap to show that part... No, not there.' Existing diary apps are often cluttered with ads and difficult to use. 'Then I should just build an app that works well for me.' This idea came to Maekawa in October 2025, at a time when he could not read a single line of code—completely new to programming.

From Zero Experience to Self-Taught Development: 'MyKarte' to 'ZutsuNote'

Maekawa dove into app development through self-study, working late into the night after putting his children to bed. After trial and error, he completed an online headache diary app called 'MyKarte' in just one month. When he began using it in his own online headache clinic, patients praised it, saying, 'I no longer need to carry a paper notebook' and 'consultations have become smoother.' It was the moment his own code solved real-world clinical problems. As his technical skills improved, MyKarte evolved into a completely new app, 'ZutsuNote,' built with professional-grade technology, and has now fully transitioned.

An easy-to-maintain headache diary with calendar and one-tap recording

From 'Vague' to 'Data-Driven' Headache Care

The more patients record, the more their headaches become 'visible'

Traditional headache treatment often relies on patients' memories, resulting in a vague understanding. With ZutsuNote, patient-recorded data is statistically analyzed and directly shared with physicians' examination screens. Headache frequency, pain intensity, duration, and medication frequency are displayed numerically at a glance. Maekawa, both the developer and a practicing headache specialist, has personally observed the following benefits in daily clinical practice:

Improved diagnostic accuracy — Accurately track progress with numerical data

Reduced consultation time — Less time spent on manual data collection and questioning

Enhanced patient understanding of their headaches — Patients can visualize their own headache patterns

Additionally, changes in data before and after starting preventive medications are visualized, aiding in monitoring treatment progress.

The value of ZutsuNote lies in sharing progress with numbers, not just a vague feeling of 'I think I'm getting better.'

How ZutsuNote Works — Patients Always Decide Whether to Share

Data sharing in ZutsuNote is entirely patient-driven.

Patients record daily headaches in ZutsuNote

Patients select and register their 'primary care institution,' after which only that institution receives the recorded data

If no primary care institution is set, data remains private and is not shared with anyone (the record belongs solely to the patient)

Since patients always retain control over data sharing, the design prioritizes privacy. For a medical institution to appear in the 'primary care' selection list, it must first register with ZutsuNote.

Security and Privacy — Because We Handle Sensitive Medical Information

ZutsuNote handles sensitive medical data (specially designated personal information) related to headaches and is therefore designed and operated with a strong focus on security and privacy.

Data storage: User records are encrypted and stored on servers within Japan (AWS Tokyo Region)

Encryption in transit and at rest: Data is encrypted both during communication (TLS) and storage

Access control and security reviews: Access to data is restricted to the minimum necessary, with regular security reviews conducted

Security management system: Organizational, human, and technical security measures are established in compliance with Japan's Personal Information Protection Act and publicly disclosed in the privacy policy

Sharing based on user consent: Medical data is shared only when users set a 'primary care institution,' and this can be revoked at any time

These are not extraordinary measures. ZutsuNote uses the same encryption technology (TLS) as online banking and e-commerce sites and stores data on AWS's domestic infrastructure in Tokyo—a global cloud platform used by financial institutions and government agencies. Despite being an app built by a single physician, it leverages world-standard systems that support critical social infrastructure. Because the developer is a practicing physician, he fully understands the sensitivity of medical information and has uncompromisingly prioritized safety.

What ZutsuNote Offers (All Free, No Ads)

Receive advance alerts about atmospheric pressure changes to prepare for high-risk headache periods

Headache logging: Easily record pain intensity, location, medication, triggers (supports migraine, tension-type, cluster, and medication-overuse headaches)

Real-time sharing with physicians: Partnered medical institutions receive patients' headache diaries directly on their examination screens

Automated international standard scores: Automatically calculates MIDAS, HIT-6, WPAI, and MIBS-4

Correlation analysis with weather: Automatically collects environmental data such as atmospheric pressure, temperature, and humidity

Headache type check and automated analysis of medication and statistics

Completely free to use with no advertisements

For Medical Institutions — Free Registration, Helps Attract Patients

ZutsuNote accepts free registration for all medical institutions. Benefits of registration include:

Appearing as a 'primary care' option for patients; once selected, their headache diary is directly delivered to your examination screen (eliminates paper collection and manual entry, allows pre-visit review of patient history)

Featured as a 'ZutsuNote Partner Medical Institution' on the public listing page, searchable by region and specialty—helping attract new patients

Only users who haven't set a 'primary care' institution will see navigation prompts to your clinic, creating new patient touchpoints

Supports online headache clinics for patients who cannot attend in person—registration and use are completely free

Medical institutions engaged in headache treatment are welcome to join. For registration, please contact us via the 'For Medical Institutions' page on ZutsuNote.

Future Outlook

ZutsuNote aims to become a user-friendly foundation for headache care, maintaining its 'completely free' model for both patients and healthcare providers. In the future, it also aims to contribute to medical research by utilizing accumulated headache data in anonymized form.