[2026] Should You Buy the 'Adult's Motivation Pen'? A Thorough Comparison with Studyplus and Forest | Recommendations for Working Professionals Who Struggle to Keep Up with Certification Studies
'I can't keep up with certification studies,' 'I want to track my study time, but I quit using apps after three days,' 'I've failed to build a study habit multiple times since becoming a working professional.'
If even one of these applies to you, this comparison article is for you.
According to a survey by Kokuyo, 71.1% of people have experienced failure in certification studies. Seven out of ten people who start studying quit halfway through.
I am a cloud engineer who has obtained 12 AWS certifications, and I can say this with certainty: the hardest part of certification study is not 'understanding,' but 'continuing.' And what you need to continue is not willpower, but a 'system that makes it easy to keep going.'
In this article, I will provide an honest comparison of five study time tracking and maintenance tools, including the currently trending IoT stationery, the Kokuyo 'Adult's Motivation Pen' (winner of the 2025 Stationery General Election Grand Prize), using the same criteria. By the time you finish reading, you should be able to decide which one you should choose.
▍Conclusion First (Type-based Diagnosis)
I will explain the rationale for each.
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▍Q1. What is the Adult's Motivation Pen? → It is a 'pen-attachable device that automatically records study time'
Conclusion: It is a small, approximately 8g device that you simply attach to the pen you normally use to automatically record the time you spend writing and studying, visualizing it in a smartphone app. 😦
Reason: Sensors detect the time the pen is moving—the amount of effort—and accumulate it as a graph in the app. You can check 'how much you studied today' in numbers rather than by feeling. 🧐
Specific Example: Think of it as a 'pedometer for studying.' Just as wearing a pedometer makes you want to walk, having a record creates a psychological effect where you think, 'I don't want to make today zero.'
Originally released in 2019 as the 'Homework Motivation Pen' for elementary school students, it was made about 60% lighter in response to requests from adults and was released to the general public as an adult version in May 2025. The fact that it is an adult version of a habit-building system that has been verified for five years with children is a point of reliability.
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▍Q2. Why don't working professionals' certification studies last? → 'Because their hard work is invisible'
Conclusion: The biggest cause of failure is not a lack of ability, but the inability to feel that you are making progress.
Reason: According to Kokuyo's survey, the top three concerns of learners are: 1) Cannot maintain motivation, 2) Cannot continue due to being busy, and 3) Cannot maintain concentration. 1 and 3 are directly linked to 'not seeing progress.' People cannot continue things where they cannot see the results.
Specific example: When I was studying for my AWS certification, I wasn't able to study for long hours every day from the start. There were days when I was too tired from work to concentrate at all. The reason I was still able to pass 12 certifications is that I kept a study log. Even on days when I could only manage 30 minutes, having a record made me feel that 'today wasn't a zero.' This feeling becomes the minimum fuel needed to sit at the desk again the next day.
In other words, the first step to making studying a habit is to create a 'recording system.' The problem is which recording tool suits you best.
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▍Q3. [Thorough Comparison] 5 Study Time Recording Tools—Motivation Pen, Studyplus, Forest, Study Timer, and Planner
I will compare 5 tools that share the same purpose of 'recording and visualizing study time' using the same criteria.
● ① Adult's Motivation Pen (9,900 yen): The only tool where you 'cannot inflate your records'
The most important aspects in this comparison are 'smartphone temptation' and 'accuracy of records.' The Motivation Pen doesn't require a smartphone while studying, and it only records the time the 'pen is actually moving.' Time spent sitting at the desk just zoning out doesn't accumulate. You can't inflate your records. Records that are too lenient on yourself don't build confidence, but records that cannot be inflated build genuine confidence. The weakness is that it cannot record 'non-writing study' such as video lectures or web-based problem sets.
● ② Studyplus (Free)—The standard tool you should try first. However, it has one structural weakness.
With features like recording by study material, graphs, and SNS sharing with peers, it is sufficient and the first thing you should try. However, it has a structural weakness: you have to touch your smartphone to record. The moment you open your phone to stop the timer, you see a notification, and before you know it, you've been on social media for 10 minutes—this is a classic scenario for failure. If you have experienced your records stopping after 3 days, the cause is not your willpower, but this structure.
● ③ Forest (Free~)—An app that grows as you 'avoid touching your smartphone'
If you leave your phone alone while the timer is running, a tree grows; if you touch it, the tree withers. The idea of completing the countermeasure against smartphone temptation within the app is brilliant. It also keeps a record of your concentration time. The weakness is that it is not suitable for managing study by material or subject. If Studyplus is a 'logbook,' Forest is a 'concentration device,' so their roles are slightly different.
● ④ Study Timer (1,000–3,000 yen)—A tool to 'segment' time. Not good for recording.
A timer that shows the remaining time improves the quality of concentration, but most models do not keep a cumulative study record. If your goal is 'visualization,' its role is different. If you use it strictly for Pomodoro, it is cheap and excellent.
● ⑤ Planner/Notebook Recording (Almost 0 yen)—You can start today. However, it also has the highest failure rate (I remember getting one in college).
It costs zero and you can start tonight. However, since both recording and continuation depend 100% on willpower, it is also the culprit behind the 71.1% failure rate. I do not recommend it to anyone who doesn't already have a habit of using a planner.
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▍Q4. Who is the 'Adult's Motivation Pen' for, and who is it not for?
<For those who are a good fit>
・People who tend to give up after three days even when they start studying for a certification (= part of the 71.1% who have experienced failure)
・People who learn by writing on paper (works well with memorization, calculation, and essay-based certifications)
・People who want to see study time in numbers rather than by feeling ・People who have tried Studyplus but stopped recording after 3 days ・People who find smartphone apps distracting rather than helpful
<For those who are not a good fit>
・People whose study is almost entirely done on PCs, tablets, or via videos → Studyplus is sufficient
・People who have already made recording a habit with an app → There is little reason to switch ・People whose biggest challenge is touching their smartphone itself → Try Forest first, and if that doesn't work, use the time-locking container at the end of this article
・People who want to study with a pencil → It cannot be physically attached
To be honest, for studies that involve long hours of hands-on work on a PC, such as AWS certifications, there will be time that cannot be recorded. In my case, since inputting by writing in a notebook to organize service names and configurations was the starting point of my learning, I feel it is a rational tool to support the continuation of that process. Please judge based on the 'percentage of time spent writing' in your own study style.
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▍Q5. Should I buy it during Prime Day? → The correct answer is to 'buy it together with other items to exceed the point redemption threshold'
Conclusion: If you are going to buy it, it is recommended to buy it together with study supplies worth 100 yen or more, such as notebooks or refill leads, during the Prime Day period ending at 23:59 on Monday, July 13.
Reason: During Prime Day 2026, if you register and purchase a total of 10,000 yen (including tax) or more during the period, you can receive additional Amazon point redemption (up to 10,000 points). The Motivation Pen is 9,900 yen. On its own, it is just 100 yen short.
Specific example: One Campus notebook and one pack of refill leads will do. Just by adding things you would use for studying anyway to your cart, you will exceed the redemption threshold, and you will get hundreds to a thousand yen worth of points back on your 9,900 yen purchase.
*Sale prices and redemption rates are subject to change. Please be sure to check the latest price on the Amazon product page before purchasing.
👉 See the current price of the 'Adult's Motivation Pen' on Amazon
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▍[Extra Edition] For those who want to 'physically seal away their smartphone' before recording
Although it falls outside the scope of this comparison, for those who say, 'I can't even start studying, and the cause is 100% my smartphone,' there are two tools that are more effective than recording tools.
● Time-locking container (2,000–5,000 yen) Put your smartphone in the box and lock it with a timer. It cannot be opened. It is the physical version of Forest, and its coercive power is the strongest. Even if used in conjunction with the Motivation Pen, the pen will still record, so they are compatible.
👉 See time-locking containers on Amazon
● Apple Watch While it is not a tool bought specifically for study recording, it is an option for those who want to turn their entire life into a habit, including exercise and sleep. During this Prime Day, the Apple Watch SE 3 is on sale, so it is a good time to buy if you were already interested.
👉 See the sale price of the Apple Watch SE 3 on Amazon
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▍Frequently Asked Questions (FAQ)
Q. Which study time tracking method is the easiest to stick with?
A. The one with the "least amount of effort required." In order of least effort: Yaruki Pen (automatic) > Forest/Apps (semi-automatic) > Planner (manual). If the act of recording itself is a hassle, you will give up on tracking. The foolproof order is to first try the free Studyplus app for 3 days; if you can't keep it up, move on to automatic tracking.
Q. What is the difference between the Adult Yaruki Pen and the Homework Yaruki Pen (children's version)?
A. The adult version features compatibility with ballpoint and mechanical pencils (the children's version is for pencils only), is approximately 60% lighter, and includes habit-forming apps designed for adults. Conversely, the adult version cannot be attached to standard pencils.
Q. Is the app paid?
A. It is basically free. There is some in-app purchase content.
Q. How long does the battery last?
A. Assuming 2 hours of study per day, it lasts about 7 days, meaning you only need to charge it once a week.
Q. I study using an iPad; can I use it?
A. It can be attached to stylus pens with a diameter of 9–13mm. Please check the diameter of the pen you are using.
Q. Isn't 9,900 yen too expensive?
A. The criterion for judgment is, "Will this prevent me from giving up even once?" Certification exam fees are often in the 10,000 to 30,000 yen range (AWS exams are 10,000 to 40,000 yen), and the cost of giving up, retaking the exam, or buying new study materials is much higher. However, this is an unnecessary investment for those who are already successfully maintaining their habits with free apps.
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▍What to do starting today
Confirm your study style—If "time spent writing on paper" accounts for more than 30% of your study time, the Yaruki Pen is a viable option. If it is zero, do not buy it.
Try tracking for 3 days with the free Studyplus app—If you can keep it up, the app is sufficient. If you give up within 3 days, that is proof that "smartphone tracking is not for you."
If your smartphone is your biggest enemy, try Forest first—You can start for free today.
If you decide to buy it, do so by Monday, July 13th, at 11:59 PM—Register for the point-up campaign and combine purchases to exceed the 10,000 yen threshold.
Consistency is not a talent; it is a system. As an investment to get outside the 71.1% failure rate, choose the tool that fits your style.
👉 Check the current price of the "Adult Yaruki Pen" on Amazon
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▍Related Articles
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