Yes, you can exchange on weekends and holidays.
USD：BUY ¥157.29/SELL ¥152.80
EUR：BUY ¥184.98/SELL ¥180.50
GBP：BUY ¥215.25/SELL ¥202.64
CNY：BUY ¥23.30/SELL ¥20.75
HKD：BUY ¥21.14/SELL ¥18.74
KRW：BUY ¥0.1203/SELL ¥0.0947
PHP：BUY ¥2.93/SELL ¥2.36
SGD：BUY ¥124.31/SELL ¥116.97
THB：BUY ¥5.25/SELL ¥4.45
CAD：BUY ¥117.00/SELL ¥108.51
AUD：BUY ¥108.97/SELL ¥97.23
NZD：BUY ¥95.03/SELL ¥84.49
CHF：BUY ¥198.13/SELL ¥191.94
TWD：BUY ¥5.41/SELL ¥4.57
MYR：BUY ¥43.25/SELL ¥34.20
VND：BUY ¥0.01/SELL ¥0.005