Yes, you can exchange on weekends and holidays.
USD：BUY ¥156.48/SELL ¥152.50
EUR：BUY ¥183.49/SELL ¥179.00
GBP：BUY ¥211.76/SELL ¥199.25
CNY：BUY ¥23.04/SELL ¥20.51
HKD：BUY ¥21.02/SELL ¥18.63
KRW：BUY ¥0.1167/SELL ¥0.0919
PHP：BUY ¥2.92/SELL ¥2.36
SGD：BUY ¥123.18/SELL ¥115.97
THB：BUY ¥5.23/SELL ¥4.42
CAD：BUY ¥115.58/SELL ¥107.13
AUD：BUY ¥107.32/SELL ¥95.66
NZD：BUY ¥93.81/SELL ¥83.32
CHF：BUY ¥195.56/SELL ¥189.17
TWD：BUY ¥5.39/SELL ¥4.61
MYR：BUY ¥42.33/SELL ¥33.59
VND：BUY ¥0.01/SELL ¥0.005