Nodonuru Wet Masks: Sleeping Pleated vs 3D and Filter Setup

Two boxes of のどぬ～るぬれマスク on a Japanese drugstore shelf both say 就寝用, meaning “for bedtime”. Are they simply masks you unwrap and put on? There are separate wet filters to insert first. The useful discovery is inside: the pleated type takes one whole filter, while the 3D type takes one on each side. That small difference tells you more about getting ready to use them than the largest number on the box.

I’m Irene, a Taiwan-born pharmacist qualified in Japan.

Japanese official information checked: 25 October 2026. This guide is for adult shoppers and compares only the unscented sleeping pleated and sleeping 3D types from Kobayashi Pharmaceutical.

Check suitability before the “10 hours” on the box

These are moisturizing masks with wet filters. The manufacturer explains that moisture in the filter becomes vapour with breathing to moisten the throat. This guide concerns these hygiene products, not throat medicines sold under the same brand. The manufacturer’s approximately 10-hour moisture-duration claim varies with the conditions of use. It is not an instruction to wear the mask for 10 hours or a guarantee that continuous wear is safe for everyone.

The instructions for these two types involve inserting wet filters before wearing the mask. Another product, のどぬ～るぬれマスク 極上加湿, has a heating element. Match the full product name rather than borrowing the heated product’s setup or instructions for another version.

Start with the boxes: three filters or three pairs?

On a phone, scroll sideways within the table.

The measurements describe different states, so comparing the numbers alone cannot guarantee which will fit your face. Unscented does not mean the filter contains only water: both unscented filters list parabens and iodine compounds. That does not make them iodine throat medicines or establish a sterilizing or treatment effect.

Pleated type: one filter, notch at the top

Open the wet-filter packet immediately before use. The original diagrams below use blue to show the structure; the actual wet filters are white.

1. Insert the filter into the inside pocket

2. Keep the pocket side towards your mouth

3. Expand the mask down to your chin

Despite its “for bedtime” name, the pleated product’s official page also explicitly permits daytime use. The suitability restrictions and instructions to stop if discomfort occurs still apply.

3D type: find the top openings and insert one per side

1. Place the two filters separately

2. Cover your nose through to your chin

After use, replace both the mask and its filters

For both types, the mask and wet filters are single-use only: do not reuse them. The official FAQ advises against washing the nonwoven mask in water, hot water or detergent for reuse because its quality may deteriorate. It also advises against adding water to a used filter: mould may develop, or it may no longer be safe to use. Rewetting is not a refill method, even when you are trying to pack light.

Keep unused sets safely stored

Store them out of reach of infants, young children and people with dementia. The manufacturer does not set a fixed expiry period, but warns that storage conditions and prolonged storage may change the quality. Do not use a filter that has dried out, smells different, is discoloured or shows other concerning changes. No stated expiry does not mean indefinite safe storage.

Dispose of them according to local rules

Do not litter. The manufacturer’s Japanese sorting examples list the box as paper, inner and filter bags as plastic, and the mask and filter as ordinary combustible rubbish. Follow the rules of the municipality where you dispose of them and ask locally if unsure; do not assume the same sorting applies in every country.

Back at the shelf: which setup do you want?

For a whole filter in one inside pocket, followed by shaping the nose wire and expanding the mask, match 就寝用プリーツタイプ / 無香料. For the 3D shape, match 就寝用立体タイプ / 無香料 and remember that you need to insert a filter on each side. Choose only after matching the box name, the filter setup and your suitability for use. “3D” describes the shape, not a stronger-effect tier.