Code point
U+3309
Glyph appearance depends on your fonts.
U+3309
So<square> 30AA 30F3 30B9U+3309 SQUARE ONSU 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+3309
13065
㌉
㌉
E3 8C 89
3309
00003309
%E3%8C%89
\u3309
\u3309
\u3309
\3309