Code point
U+3333
Glyph appearance depends on your fonts.
U+3333
So<square> 30D5 30A3 30FC 30C8U+3333 SQUARE HUIITO is a Unicode 16.0.0 character in the Other Symbol category. It belongs to the CJK Compatibility block.
Choose the representation you need, then copy its value.
U+3333
13107
㌳
㌳
E3 8C B3
3333
00003333
%E3%8C%B3
\u3333
\u3333
\u3333
\3333