Fortnite the character?

Hi

I wanted to add someone to fortnite but have such a sign and does anyone know how to do it or what that is? Oh and that's not an E.

The japanese character Mii / mi / San / 3 三 probably

Yes, I know that the number is 3 but how can I write that on the switch

At the keyboard at the bottom left the internet symbol so this ball then change the language to japanese and then you enter mii then click the autocorrection