Yes, you can exchange on weekends and holidays.
USD：BUY ¥154.98/SELL ¥150.50
EUR：BUY ¥178.78/SELL ¥174.15
GBP：BUY ¥207.17/SELL ¥194.20
CNY：BUY ¥22.68/SELL ¥20.10
HKD：BUY ¥20.91/SELL ¥18.48
KRW：BUY ¥0.1191/SELL ¥0.0940
PHP：BUY ¥2.91/SELL ¥2.31
SGD：BUY ¥121.24/SELL ¥114.01
THB：BUY ¥5.11/SELL ¥4.29
CAD：BUY ¥112.61/SELL ¥104.05
AUD：BUY ¥105.17/SELL ¥93.19
NZD：BUY ¥92.20/SELL ¥81.51
CHF：BUY ¥192.73/SELL ¥186.39
TWD：BUY ¥5.42/SELL ¥4.57
MYR：BUY ¥41.12/SELL ¥32.56
VND：BUY ¥0.01/SELL ¥0.005