Yes, you can exchange on weekends and holidays.
USD：BUY ¥160.98/SELL ¥157.00
EUR：BUY ¥188.18/SELL ¥183.60
GBP：BUY ¥219.95/SELL ¥206.38
CNY：BUY ¥24.45/SELL ¥22.85
HKD：BUY ¥21.49/SELL ¥19.16
KRW：BUY ¥0.1191/SELL ¥0.0945
PHP：BUY ¥2.88/SELL ¥0.28
SGD：BUY ¥127.40/SELL ¥119.35
THB：BUY ¥5.21/SELL ¥4.40
CAD：BUY ¥120.04/SELL ¥110.68
AUD：BUY ¥117.94/SELL ¥106.67
NZD：BUY ¥98.00/SELL ¥86.58
CHF：BUY ¥201.84/SELL ¥195.59
TWD：BUY ¥5.49/SELL ¥4.63
MYR：BUY ¥45.11/SELL ¥35.69
VND：BUY ¥0.01/SELL ¥0.004