Yes, you can exchange on weekends and holidays.
USD：BUY ¥157.98/SELL ¥153.50
EUR：BUY ¥188.98/SELL ¥182.30
GBP：BUY ¥217.54/SELL ¥204.85
CNY：BUY ¥23.63/SELL ¥21.02
HKD：BUY ¥21.15/SELL ¥18.75
KRW：BUY ¥0.1187/SELL ¥0.0937
PHP：BUY ¥2.96/SELL ¥2.38
SGD：BUY ¥126.10/SELL ¥119.01
THB：BUY ¥5.31/SELL ¥4.49
CAD：BUY ¥118.29/SELL ¥109.91
AUD：BUY ¥115.13/SELL ¥103.70
NZD：BUY ¥99.27/SELL ¥89.03
CHF：BUY ¥202.37/SELL ¥196.36
TWD：BUY ¥5.40/SELL ¥4.57
MYR：BUY ¥44.61/SELL ¥35.40
VND：BUY ¥0.01/SELL ¥0.004