One of the more psycho things about Japanese is that EVERY OBJECT EVER uses ENTIRELY DIFFERENT WORDS for counting itself.
And each method of counting has its OWN KANJI.
For example, sheets of paper are 一枚、二枚、三枚 （ichimai, nimai,sanmai), but oranges and apples are 一個、二個、三個 (ikko,niko, sanko)。
Any kanji that is used to count something gets the COUNTER tag.
KANJIDAMAGE