[Translation from Japanese to English ] As we can wear it for a cloth in the house in winter in Japan, it does not ma...

Original text

日本では寒い季節に部屋着として着用される為、汗をかいたり汚れが着いたりすることは稀ということで洗濯の頻度は１シーズンに１回、つまり冬に着用して春か夏の暖かくなってきたシーズンに１回手洗いして、乾いたらそのままクローゼットに仕舞い、また寒い季節に着用するのが一般的です。
頻繁に汚れるようであっても２週間に１回程度、優しく手洗いただけると長く着用できるかと思います。
また、洗濯とは別に良く晴れた日に濡れていない状態のはんてんを天日干ししていただくと、綿がふっくら膨らんで暖かくオススメ

Translation / English

As we can wear it for a cloth in the house in winter in Japan, it does not make dirty with sweat or dirt much and so it is washed once a year, in short, you wear it in winter, wash it in spring or summer and keep it in a closet until a cold season comes in, it is a general way.
Even it gets dirty so often, it would be used for a long time by washing once 2 weeks.
Also, apart form washing, when the weather is fine, you can put it under shed even if it is not wet, its cotton bets soft and warm which I recommend you.

Translation / English

In Japan, it is used as an outfit worn in the house in cold season. For this reason, as a person who wears it hardly has the sweat and dirt on it, we usually handle it as follows.
We wash it once in 1 season. In other words, we wear it in winter and wash it by hand once in warm season such as spring and summer. After it is dried, we put it into the closet and wear it in the cold season again.
If it gets dirty often, you can use it for a long time by washing it by hand carefully once 2 weeks.
In addition, if you dry the dried hanten (short winter coat) in the sun on the very clear day other than washing it, the cotton is swollen where you feel warm. I recommend it to you.

Translation / English

As it's wore as a room wear for a cold season in Japan, it's thought not to get too dirty with sweats or stains. Therefore it's generally washed once in a season in the other words, people wear it in winter then hand wash it in a warm season like spring or summer then put it in a closet once dried and wear again in a cold season.
Even it's get dirty often, if you hand wash it once a two weeks then its life would get longer.
Besides washing, we recommend to hang it being dry outside when it's nice sunny day. It makes the cotton fluffy & warm.

Translation / English

Since it is worn as at-home clothes in cold season in Japan when you don't sweat very much or it would rarely get stains, frequency of washing is generally once in a season; which means that you wear it in winter, hand-wash in spring or summer when it gets warmer, put it in closet when dried and then wear it again in cold season.
Even if it gets dirty very often, please just try to wash it by hands gently once in every two weeks so that you can wear it for long time.
Also aside from washing, we recommend you to put the dried Hanten in the sunshine on a sunny day which makes the cotton fluff and warmer.