Electric blankets that cost ¥22 a month to run: 5 picks

Five electric blankets in Japan, from ¥2,850 to ¥9,083
Two sizes: 140×80 cm under-blankets and 188×130 cm over-and-under ones
Two have timers: Yamazen’s sleep timer, Koden’s bedtime and morning timers

The five

Best for	Where to get it	Score	Street price, incl. tax
Cheapest to buy and near-cheapest to run, with 1,244 reviews — if you can’t decide	Sugiyama Boseki heated under-blanket See price	77/100	¥2,850 (street price)
One button, four hours of power out of eight, about ¥96 a month	Yamazen heated under-blanket with sleep timer See price	76/100	¥6,980 (street price)
The 188×130 cm standard, with 1,290 Rakuten reviews	Sugiyama Boseki over-and-under blanket See price	73/100	¥4,380 (street price)
188×130 cm at about 31 Wh — the cheapest large one to run	Koden over-and-under blanket See price	73/100	¥4,300 (street price)
Off as you fall asleep, on before you wake	Koden over-and-under blanket with bedtime and morning timers See price	67/100	¥9,083 (street price)

These are sold on Rakuten Ichiba, which generally ships within Japan only, and they run on Japanese mains power (100V, 50/60Hz). They suit a home in Japan rather than a suitcase.

Cheapest to buy and near-cheapest to run, with 1,244 reviews

Sugiyama Boseki heated under-blanket

Sugiyama publishes consumption for all three settings: about 31 Wh on high, about 3 Wh on low
Heating wires concentrated towards the foot end: a cool head and warm feet
Room-temperature sensor and a dust-mite programme

See today’s price on Rakuten→

Why it made the five

About ¥1.0 an hour on high, about ¥0.1 on low
A room-temperature sensor that adjusts the heat as the night gets colder
A dust-mite programme, and the wiring weighted towards your feet
Right for: A first blanket, bought as cheaply as possible.
Not for: Wanting a timer to cut the power automatically.
Worth knowing: No timer is listed. At 140×80 cm it is made to lie under you, not to wrap around you.

Score breakdown — 77/100

Criterion	Stars	Why
Quality	★★★★☆	About 140×80 cm as an under-blanket earns three stars, and the room-temperature sensor earns one more. Surface temperature about 52°C on high, 36°C medium, 20°C low
Value for money	★★★★★	¥2,850 on Rakuten earns five. On high, 31 Wh × ¥31 = about ¥1.0 an hour, and 8 hours × 30 nights = 7.44 kWh × ¥31 = about ¥231 a month, so no deduction. On low, 3 Wh × 240 hours = 0.72 kWh = about ¥22 a month
Easy to live with	★★☆☆☆	No timer or shut-off is listed, and the product page says only ‘fully washable’ without explaining the controller or the machine settings, so one off
Trust	★★★★☆	4.35 across 11,841 reviews on four sites
Only here	★★★★☆	The cheapest of the eight to buy, and still has the sensor, the dust-mite programme and the foot-weighted wiring

One button, four hours of power out of eight, about ¥96 a month

Yamazen heated under-blanket with sleep timer

Press the button at bedtime: two hours of heat, four off, then two more before you wake
Power is on four hours out of eight
Fits under you on a futon or sofa, or over your legs

See today’s price on Rakuten→

Why it made the five

Sleep timer: two hours of heat, four off, two more before morning
About ¥0.8 an hour on high, or about ¥96 for the month using the timer
Shuts off automatically twelve hours after being switched on
Right for: Waking up too hot in the middle of the night, and wanting the bill cut every night without thinking about it.
Not for: Wanting heat all night — four hours of it are off.
Worth knowing: The 134 reviews are the combined total for this and the over-and-under version on the same listing. That larger version showed no restock date on Rakuten as of 21 September 2026. The controller cannot be washed.

Score breakdown — 76/100

Criterion	Stars	Why
Quality	★★★☆☆	About 140×80 cm as an under-blanket earns three stars. No room-temperature sensor is listed for this model number. Surface temperature about 23°C low, 33°C comfortable, 53°C high
Value for money	★★★★☆	¥6,980 on Rakuten earns four. The maker’s figure of about ¥0.8 an hour on high × 8 × 30 = about ¥192 a month, so no deduction. With the sleep timer the power is on four hours of the eight: ¥0.8 × 4 × 30 = about ¥96 a month
Easy to live with	★★★★★	The sleep timer earns one and the twelve-hour shut-off another. The maker states that the blanket is washable and the controller is not
Trust	★★★☆☆	4.36 across 134 Rakuten reviews
Only here	★★★★☆	The only one of the eight that switches itself between falling asleep, deep sleep and waking on a single press, halving the bill without turning the heat down

The 188×130 cm standard, with 1,290 Rakuten reviews

Sugiyama Boseki over-and-under blanket

Per setting: about 50 Wh on high (about ¥1.6 an hour), 27 medium, 5 low (about ¥0.2)
Room-temperature sensor, dust-mite programme and foot-weighted wiring

See today’s price on Rakuten→

Why it made the five

About 188×130 cm, usable over or under you
Published consumption for all three settings: about 50, 27 and 5 Wh
Room-temperature sensor, dust-mite programme, foot-weighted wiring
Right for: Wanting one blanket to do both jobs, and wanting reviews to read first.
Not for: Wanting a timer to cut the hours of power.
Worth knowing: Left on high it comes to about ¥372 a month at eight hours a night. Turning it to medium or low once you are asleep is where the saving is. No timer is listed.

Score breakdown — 73/100

Criterion	Stars	Why
Quality	★★★★★	About 188×130 cm over-and-under earns four stars, and the room-temperature sensor one more. Surface temperature about 52°C high, 36°C medium, 20°C low
Value for money	★★★★☆	¥4,380 on Rakuten earns five, but on high 50 Wh × ¥31 = about ¥1.6 an hour and 8 × 30 = 12.0 kWh × ¥31 = about ¥372 a month, which is over ¥300, so one off. On low, about ¥37 a month
Easy to live with	★★☆☆☆	No timer or shut-off is listed, and the page says only ‘fully washable’, so one off
Trust	★★★★☆	4.28 across 8,749 reviews on four sites
Only here	★★★☆☆	The most-reviewed over-and-under of the eight, but no figure or function here belongs to it alone

188×130 cm at about 31 Wh — the cheapest large one to run

Koden over-and-under blanket

About 31 Wh an hour on high, about ¥1.0 at ¥31 per kWh
Koden states it uses about 38% less than its own previous model
Sliding temperature control and a dust-mite programme

See today’s price on Rakuten→

Why it made the five

About 31 Wh on high — about ¥231 for a month of eight-hour nights
About 38% less than the maker’s own previous model, by their figures
The controller detaches so the blanket can go in the machine
Right for: Wanting the large size with both the purchase price and the bill kept down.
Not for: Wanting a timer to manage the heat while you sleep.
Worth knowing: No timer and no room-temperature sensor are listed. There is one Rakuten review so far. Detach the controller before washing, and do not use a front-loading drum machine.

Score breakdown — 73/100

Criterion	Stars	Why
Quality	★★★★☆	About 188×130 cm over-and-under earns four stars. No room-temperature sensor is listed. Polyester throughout; surface temperature about 52°C high, 36°C medium, 20°C low, with a sliding control
Value for money	★★★★★	¥4,300 on Rakuten earns five. On high, 31 Wh × ¥31 = about ¥1.0 an hour and 8 × 30 = 7.44 kWh × ¥31 = about ¥231 a month, so no deduction. On low, about ¥22 a month
Easy to live with	★★★☆☆	No timer or shut-off, so no addition, but the maker does explain detaching the controller, using a laundry net, and avoiding drum machines, so no deduction either
Trust	★★☆☆☆	5 across 2 reviews on two sites
Only here	★★★★☆	Tied for the lowest consumption among the over-and-under models at about 31 Wh on high, with a published 38% improvement on the maker’s previous model, and it is the cheapest of them

Off as you fall asleep, on before you wake

Koden over-and-under blanket with bedtime and morning timers

The same 55 W element and 31 Wh on high as the VWK551H-DS, with two timers added
The morning timer switches the power on so the bed is warm before you get up
Fabric treated against bacteria and odour

See today’s price on Rakuten→

Why it made the five

Bedtime timer: cuts out one or two hours after you switch on
Morning timer: comes on four to eight hours later
About 31 Wh on high, with an automatic shut-off twelve hours after switching on
Right for: Wanting the bed cold while you sleep and warm when the alarm goes.
Not for: Keeping the purchase price down — it is about twice the VWK551H-DS.
Worth knowing: Two Rakuten listings as of 21 September 2026 and no reviews yet. No room-temperature sensor is listed.

Score breakdown — 67/100

Criterion	Stars	Why
Quality	★★★★☆	About 188×130 cm over-and-under earns four stars. No room-temperature sensor is listed. The pile is half polyester, half acrylic, treated against bacteria and odour; surface temperature about 52°C high, 36°C medium, 20°C low
Value for money	★★★☆☆	¥9,083 on Rakuten earns three. On high, 31 Wh × ¥31 = about ¥1.0 an hour and 8 × 30 = 7.44 kWh × ¥31 = about ¥231 a month, so no deduction. On low, about ¥22 a month
Easy to live with	★★★★★	The one- and two-hour bedtime timer earns one and the twelve-hour shut-off another, and the maker explains detaching the controller for washing
Trust	★☆☆☆☆	No reviews yet on the two Rakuten listings as of 21 September 2026
Only here	★★★★☆	The only one of the eight with a separate timer to switch off and another to switch on, keeping the lowest large-size consumption while cutting the hours of power as well

Know before you buy

On the highest setting, eight hours a night for thirty nights costs between about ¥96 and ¥372. On the lowest setting the same month costs about ¥22.
That is the whole argument for a blanket. A room air conditioner fighting a January night in an uninsulated flat costs several thousand yen a month.
Under-blankets use less than over-and-under ones. The cheapest here draws about 21 Wh an hour on high; the largest over-and-under draws about 62.
Two models solve the real problem of a heated bed, which is waking up too hot at two in the morning: one heats, stops for four hours, then heats again before you wake.
All five can be put in a washing machine with the controller detached, and all five have a dust-mite programme — in a humid Japanese summer, that matters for bedding that lives in a cupboard.
We priced electricity at ¥31 per kWh, roughly the current national average, and show the multiplication for every model so you can redo it with your own rate.

How we chose: theme, conditions, scoring

How we chose

Candidates: 125
Met every condition below: 81
Kept: five, each the best at something different

Conditions (all of them, not most of them)

The maker’s own site states that the blanket is machine washable and has a dust-mite programme
The maker publishes the hourly running cost, or the hourly consumption in watt-hours
Large enough for a single futon or bed (130×80 cm or more for an under-blanket, 188×120 cm or more for an over-and-under)
Buyable new on Rakuten Ichiba, stock confirmed by model number on 21 September 2026

Scoring

Five criteria, one to five stars each, weighted to one hundred points. Every star says where the number came from.

Quality20 pts
- Set by size: an under-blanket of 130×80 cm two stars, 140×80 cm three, an over-and-under of 188×120–130 cm four, 200×140 cm or larger five. Add one where the maker states a room-temperature sensor that adjusts the heat automatically, to a maximum of five.
Value for money25 pts
- The cheapest price on Rakuten Ichiba: under ¥5,000 five stars, under ¥8,000 four, under ¥12,000 three, ¥12,000 or more two. Subtract one where eight hours a night for thirty nights on the highest setting exceeds ¥300 a month.
Easy to live with20 pts
- Starts at three stars. Add one for a timer that switches the power according to when you go to bed and get up, and one for an automatic shut-off. Subtract one where the maker’s site does not say how to detach the controller for washing, or which parts cannot be washed.
Trust20 pts
- Review counts on Rakuten Ichiba listings found by model number: 100 or more with an average of 4.3 or better five stars, 30 or more four, 10 or more three, 1–9 two, none yet one.
Only here15 pts
- Starts at three stars. Add one or two where a figure or function belongs to this model alone among the eight, and where it bears directly on the bill, on getting to sleep, or on washing.

What we dropped

Candidate	Verdict	Why
Panasonic electric under-blanket, single S	Runner-up (65/100)	65 points, below the lowest of the five (67)
Yamazen flannel electric under-blanket	Runner-up (60/100)	60 points, below the lowest of the five (67)
Panasonic electric over-and-under blanket, single L	Runner-up (53/100)	53 points, below the lowest of the five (67)
Koden VWS401H-DB	Runner-up	A 130×80 cm under-blanket at about 23 Wh on high and ¥2,200 on Rakuten. Cheap to run, but it covers the same ground as Sugiyama’s NA-023S, which is larger, has the sensor, and has 1,244 reviews.
Koizumi KDS-40251	Runner-up	A 130×80 cm under-blanket at about 27 Wh, ¥2,921 on Rakuten, but no room-temperature sensor and the same role as the NA-023S.
Koizumi KDK-75258T	Runner-up	A 188×120 cm over-and-under with a sleep timer and twelve-hour shut-off, but about 57 Wh on high — nearly double Koden’s CWK551BG-BS for the same function.
Koden VWB101RM-MM	Runner-up	A 188×160 cm semi-double at ¥11,626, but about 62 Wh on high. For the large size we took Panasonic’s DB-R41L, which is 200×140 cm at about ¥1.7 an hour.
Panasonic DB-RM4M	Runner-up	A 188×137 cm over-and-under in microfibre on both sides, but the same running cost as the DB-R41L at ¥19,300.
Yamazen YMK-PTS62	Held back	The 188×130 cm version of the YMS-PTS42 with the same sleep timer, but the Rakuten listing showed no restock date for the large size on 21 September 2026.
Iris Ohyama EHB-1408-T and EHB-1913-T	Outside the theme	Plenty of Rakuten reviews, but no hourly consumption or cost published on the maker’s site.
Sugiyama Boseki SSW20KW10, SB22K25 and others	Outside the theme	Hourly consumption is published, but the product pages do not state washability or a dust-mite programme.
Nitori washable electric blankets, eight models	Outside the theme	Sold only through Nitori’s own shops and website, with no Rakuten listings.
Hitachi electronically controlled blankets	Outside the theme	Hitachi’s own support site shows the whole range as discontinued.

Questions visitors ask

Is an electric blanket really cheaper than the air conditioner?

For sleeping, by a wide margin. The most expensive of these five costs about ¥372 for a month of eight-hour nights on its highest setting, and the cheapest about ¥96. A room air conditioner heating an uninsulated Japanese flat through January runs into the thousands of yen a month. The blanket does not warm the room, so it does not help at your desk — but it solves the bed.

Which one is cheapest to run?

Among under-blankets, the Yamazen YMS-FK35 at about 21 Wh an hour on high, which is about ¥0.7 an hour or ¥156 a month. Among the over-and-under models, Koden’s VWK551H-DS and CWK551BG-BS at about 31 Wh, about ¥231 a month. All of these figures are for the highest setting; on low, several of them come to about ¥22 a month.

Under-blanket or over-and-under?

Under, if the bill is what you care about. Comparing Koden’s two efficient models, the under-blanket VWS401H-DB draws about 23 Wh on high against the over-and-under VWK551H-DS at about 31. If you want to pull it over your legs on the sofa or wrap yourself in it, the 188×130 cm over-and-under is the size that works.

Any of them have timers?

Yamazen’s YMS-PTS42 has a sleep timer that heats for two hours, stops for four and heats for two more, so the power is on four hours out of eight. Koden’s CWK551BG-BS lets you pick a cut-out one or two hours after bedtime and a switch-on four to eight hours later. Both shut off automatically after about twelve hours.

Can I wash it?

All five, with the controller detached first. Koden’s instructions add a laundry net and warn against front-loading drum machines. Yamazen states that the controller itself is not washable. Combined with the dust-mite programmes, this is why we made both conditions mandatory — bedding that lives folded in a Japanese cupboard through a humid summer needs to be washable.

Why no Nitori or Iris Ohyama?

Nitori’s electric blankets are sold only through Nitori’s own shops and website, with no Rakuten listings. Of Iris Ohyama’s six models, two publish an hourly cost, but only for the lowest setting, so we could not compare them on high.

Can I take one home with me?

These run on Japanese 100 V mains, so they are for a home here rather than a souvenir. If you are spending a winter in Japan, this is the cheapest heating purchase available.

Changes

2026-10-25　First published. Scored from 125 candidates.