5 Examples of Japanese Universal Design: Otohime, Milk Carton Notches, Shampoo Bottle Markings, and Disaster Vending Machines

Everyday items in Japan often go viral on social media for their "thoughtful designs": restroom devices that play running water sounds, small notches on the tops of milk cartons, tactile ridges on the sides of shampoo bottles, elevators that allow you to cancel accidentally pressed floors, and vending machines that can even provide free beverages during disasters.

The true value of these designs is not that Japanese people are inherently magical, but that they transform real-world problems—such as embarrassment, poor visibility, accidental inputs, inability to distinguish between products, and loss of function during disasters—into intuitive prompts that require no instruction manual. However, online images often mistakenly portray the functions of specific brands or certain models as universal standards across Japan.

This article will clarify the distinction between universal designs, specific product features, and potentially inaccurate online claims. In practice, you should always rely on device labels and manufacturer guidelines.

What is human-centered design?

Human-centered design starts with the user's body, emotions, abilities, and environment, rather than prioritizing aesthetics. It asks:

• Where is the user most likely to make a mistake?
• Can it still be used if the person cannot see, cannot hear, or has limited hand dexterity?
• Is the function easy to understand even when the user is stressed?
• Can the problem be solved without causing embarrassment?
• Is there a backup plan in case of power outages, earthquakes, or system failures?

Good design does not have to be expensive. A notch, a raised line, or a sound button can be more effective than a complex screen.

1. Japan's "Otohime" (Sound Princess) in restrooms: Not just for privacy, but for water conservation

Many public women's restrooms in Japan are equipped with an "Otohime" (Sound Princess) device. When activated by a button or a motion sensor, it plays the sound of running water to mask bathroom noises. This design addresses privacy and embarrassment, but also serves to conserve water.

In the past, some users would flush repeatedly to mask sounds, leading to excessive water consumption. By replacing extra flushing with an electronic sound, the design addresses both psychological comfort and resource efficiency. After TOTO introduced the "Otohime" in the 1980s, similar features became increasingly common and are now often integrated into the control panels of smart toilets.

Is the Otohime only for women?

It was initially closely tied to the culture of women's public restrooms, but the need for acoustic privacy is not exclusive to women. Some men's restrooms, accessible restrooms, or universal restrooms may also be equipped with similar features.

What is the core design focus?

• Treating "unspeakable" embarrassment as a genuine need.
• Not requiring the user to explain their needs to others.
• Using low-resource methods instead of repeated flushing.
• Ensuring that buttons, sensors, and volume controls are easy to understand.

Design Insight: Emotional privacy is a functional necessity, not an optional luxury.

2. Notches on milk cartons: Letting fingers identify what eyes cannot

In Japan, many milk products in gable-top cartons of 500ml or more feature a semi-circular notch at the top. This tactile mark is primarily intended to help visually impaired individuals identify pure milk and can also indicate the side from which the carton opens.

The brilliance of this design is that it requires no electronic components, batteries, or smartphones. Users simply need to feel the notch to gain additional information.

Do all milk cartons have this notch?

No. The notch is related to specific Japanese containers, sizes, and the classification of "milk" (gyu-nyu). Milk-based beverages, processed dairy products, juices, small-size cartons, or different packaging types may not use it. Furthermore, it is not the only way to identify product content; one should still check the text, Braille, or ask a shop clerk for assistance.

Why is the notch placed on the side opposite the opening?

Common designs use the notch to indicate which side is *not* the primary opening, making it easier for users to determine the correct direction to open it. However, packaging styles vary, so one should always follow the arrows and fold lines on the carton itself.

Design Insight: A single detail can provide two layers of information simultaneously: "what this is" and "how to use it."

3. The elevator "undo button": Can you really cancel a wrongly pressed floor?

Some elevators in Japan have a function to cancel wrongly selected floors. Common operations might involve quickly pressing the lit floor button twice, though some models may require a long press or another method. If successful, the button light will turn off, or the floor selection will be canceled.

Should you keep testing this in unfamiliar elevators?

No. If you press the wrong floor, try the method clearly indicated by the elevator's signage; if there is no indication, it is generally safer to let the elevator stop at the wrong floor than to repeatedly press buttons randomly. Do not press the emergency button.

Why is this feature not standardized across the board?

Elevator control involves safety, operational efficiency, access control, and fire modes. Requirements for residential buildings, hospitals, hotels, and offices differ, and the cancellation function may even be disabled by building management.

Design Insight: A good system not only prevents errors but also allows users to correct them at a low cost.

4. Tactile ridges on shampoo bottles: Distinguishing in a slippery bathroom

Many shampoo bottles in Japan feature tactile ridges or bumps on the side or near the pump head, while conditioner bottles typically do not have these markings. Users can distinguish between the two by touch alone, without needing to read the text.

This is especially important for the visually impaired, and it is also convenient for anyone not wearing glasses, washing their eyes shut, or using products where labels are blurry from steam or the packaging shapes look similar.

Is this Braille?

Usually, it is not full Braille. It is a simple, cross-linguistic tactile symbol intended not to spell out the word "shampoo" but to allow users to quickly differentiate between two types of products.

Are the marks the same for all brands?

There is long-standing industry standardization and promotion in Japan, and many brands adopt similar practices; however, different containers and overseas versions may differ. After purchasing, it is wise to feel the bottle to familiarize yourself with it, and do not assume all ridges represent the same contents.

Design Insight: In environments where reading is most inconvenient, visual labels should not be the only source of information.

5. How do vending machines manage hot and cold drinks?

Japanese vending machines can provide both cold and hot drinks in a single unit, managing products through different temperature zones, insulation, cooling, and heating systems. Near the buttons, you will often see blue "tsumetai" (cold) and red "attakai" (hot) labels.

Modern machines also use energy-saving controls, adjusting operations based on time of day, sales volume, season, or internal status. Some equipment is equipped with remote monitoring, allowing operators to track inventory, malfunctions, and temperature information.

Can you see the internal temperature by long-pressing the buttons?

This is not a public feature applicable to all Japanese vending machines. Some models may have maintenance diagnostic or display modes, but the average customer should not assume that long-pressing a price button will reveal the internal temperature, and one should not attempt to test the device's maintenance functions.

Consumers should rely on the heat/cold labels, the product's condition, and the vending machine's instructions. If the beverage temperature or quality is clearly abnormal, contact the operator listed on the machine.

Disaster-ready vending machines: Do they really give away drinks for free during an earthquake?

Some public facilities, schools, train stations, or areas near evacuation shelters in Japan are equipped with "disaster-ready" vending machines. In the event of a major disaster, after being activated by management, a remote system, or designated manual operation, the drinks inside can be made available to those affected.

What other functions do disaster-ready vending machines have?

• Providing stocked beverages under specified conditions.
• Displaying disaster information or local announcements.
• Equipped with backup power or manual operation options.
• Serving as a logistical hub for cooperation between local governments, site operators, and beverage companies.

Its value is not just as a machine that sells drinks, but as a piece of everyday commercial equipment that converts into public infrastructure during a disaster.

Common principles of these 5 designs

Are these designs only found in Japan?

No. Accessible packaging, tactile markings, water-saving devices, error-tolerant interfaces, and disaster backup systems are implemented all over the world. Japanese examples receive particular attention partly because they appear so frequently in public life and are visually distinct, making them easy for travelers to notice and share.

Dismissing all such thoughtful designs as merely "the Japanese being naturally detail-oriented" overlooks what is truly important: users voiced needs, companies were willing to standardize, the government or industry established specifications, and the market accepted the additional design costs to accommodate minority groups.

What is the difference between human-centered design and inclusive (accessible) design?

The two overlap significantly, but their focus differs slightly:

• Human-centered design: Starts with user needs and usage contexts, iteratively testing solutions.
• Inclusive/Accessible design: Focuses on removing barriers that prevent people with disabilities from using products, spaces, or services.
• Universal design: Aiming to make products usable by as many people as possible—regardless of age, ability, or background—without requiring specialized adaptations.

The milk carton notch originally served the visually impaired but also helps the general population identify the opening; the shampoo ridges similarly benefit anyone washing with their eyes shut. This is the classic "curb-cut effect" of universal design: after improving things for a specific group, more people benefit as well.

Well-intentioned design can also fail

Without standards, users cannot learn

If every brand uses different tactile symbols, the visually impaired must memorize them one by one, increasing the burden. Standardization allows a single learning experience to apply across multiple products.

Functions exist, but without clear prompts

An elevator may allow floor cancellation, but if the operation method is not indicated, users may not dare to try. If a hidden function cannot be discovered, its value drops significantly.

Using minority groups as marketing props

If a design is promoted purely with "moving stories" without inviting actual users to test it, the result may be a product that looks thoughtful but is actually difficult to use.

Convenience masking privacy and maintenance issues

Networked vending machines and smart devices allow for remote management but also increase demands for data, cybersecurity, and maintenance. Human-centered design concerns itself not just with the initial use, but also with long-term reliability.

What can brands and shops learn?

• Do not rely on color alone for information: Use a combination of text, shape, icons, and touch.
• Allow customers to correct mistakes: Cancellation, "back," and "reselect" options should be clearly visible.
• Test in real environments: Wet hands, bright light, noise, wearing gloves, and being in a rush all change how things are used.
• Pre-design for failure modes: If there is a power or internet outage, can customers still complete basic operations?
• Protect dignity: People who need assistance should not be forced to publicly explain their physical conditions or difficulties.

FAQ

What is the Japanese Otohime?

The Otohime is a bathroom device that plays the sound of running water to mask the sound of using the toilet, which can also reduce the waste caused by repeated flushing.

Why do Japanese milk cartons have a notch?

Some pure milk cartons of 500ml or more feature a semi-circular tactile notch, mainly to help the visually impaired identify the milk and to indicate the opening direction.

Can all elevators in Japan cancel floors?

No. Some models allow cancellation through double-clicking, long-pressing, or other operations, but the feature varies by manufacturer and building settings.

How do you distinguish between Japanese shampoo and conditioner?

Many shampoo bottles have tactile ridges, while conditioner bottles typically do not. You should still check the labels or brand instructions for your specific product.

Do Japanese vending machines automatically become free during an earthquake?

Not all vending machines have this function. Some disaster-ready units can be activated for free distribution by management or system operators under specific conditions.

Can Japanese vending machines display their internal temperature?

Some units have maintenance monitoring features, but general customers should not assume that long-pressing a button will display the temperature. Always rely on the cold/hot labels on the machine and official instructions.

What is universal design?

Universal design is the effort to make products, spaces, or services usable by people of different ages, abilities, and backgrounds without requiring extra modifications or special assistance.

Conclusion: True thoughtfulness means no one has to ask for help

The most valuable lesson from these Japanese everyday designs is not to package every detail as a cultural miracle, but to acknowledge that users will feel embarrassment, may not see well, will make mistakes, and might lose their usual support systems during a disaster.

A notch, a ridge, or a cancellation action may seem minor, but they return choice and dignity to the user. The best kindness is not deciding for others, but enabling more people to accomplish things on their own.