Yes you can.
Yen time deposits and 2 Weeks Maturity Deposits can be cancelled before the maturity date on PowerDirect (Internet banking).
●From the PC●
From the Shinsei Power Direct “TOP” screen, select “Yen Deposit” from the upper menu, and select “Inquiry Yen Deposit ” from the menu directly below.
Please confirm your desired deposit, select "Redemption" and follow the instructions on the screen to complete the cancellation procedure.
● From the smartphone ●
On Smartphone screen, Tap MENU .
Please click on the “Yen Deposit” → “Inquiry Yen Deposit” and follow the instructions on the screen to complete the cancellation procedure.