Rakuten Japan Credit Card Payment

I notice I wasn't asked to input the 3 digits security number on the back of the card.

Is that going to be inputted later after I received the goods?

My Japanese is not really good, so I'm not so sure.

I assume you are trying to make a purchase at a shop on Rakuten.co.jp mall, and entering credit card number as payment method. If the order went through, and if you receive a confirmation e-mail, that was it. May online shops do not ask for the security code on the back of the card.

I see.

I thought they couldn't charge without the 3 digits number?

I have receive the order confirmation. Is there anything I must do?

After I received the stuffs, is there any button that I should click to confirm that I have received the item?

As with all credit card, the three numbers at the back of the card is usable when you type in the 16 digit credit card number, if they don't ask for it then, it's not needed.

some earlier/older online system does not use this, but as a security measures I think it's best to have it.

I'm referring to a Hong Kong credit card, but it should be the same with all.