If you have your family name in Kanji and you wanna get an 印鑑 (name stamp), be it for your bank account or what not, you can most likely find one off the Daiso racks which really costs just ￥105 (including taxes). But you’ll also have to buy a separate ink pad which usually has a small area for you to store your name stamp together. That’d be another ￥105.
So you drop by Daiso and you see all the name stamps in all their glory beckoning you to take them home. Suddenly, in the corner of your eye, you spot a jewel. It screams at you, “Take me home~ I’m a self-inking stamp!” Your eyes light up. Yeah baby! What a deal!
But! Before you go all high and start digging out 105 pieces of ￥1 coins, I have one word for you.
Why not? The reason is simple. Self-inking name stamps cannot be used for official documents. And why is that? Because every single one is exactly the same. What do I mean by that? Now, my family name is 林, which is really an easy find and every single self-inking name stamp that reads 林 is manufactured exactly the same way. Which means that, anyone can buy another one and forge my identity.
Yes, this means those that are not self-inking, even if they all read 林, they are different. We can’t tell with our naked eyes but banks have the equipment to verify the details.
Case in point:
A former colleague who lost her name stamp thought she could just buy another one, which she did. When she used it at her bank, she was told that the name stamp she’s using is different from the one she registered before.
On a more random note, there’s another reason why you shouldn’t pay for your ￥105 item with 105 pieces of coins. It is illegal. Most people (even Japanese) do not know about this but making payments with more than 20 pieces of coins can be considered harassment. It’s really up to each supermarket or cashier to accept your payment but they also have the right to report you.