Ha! Redo - that's funny.
Most female koi have a wider rib cage than males (to provide space for the eggs). Males have fins that are longer and may have a rough outer edge. When they are younger, a softer, whiter nose may indicate femininity.
Males tend to "finish" or reach their maximum beaty potential earlier.
If you are VERY careful, you can squeeze along the tummy line. Both males ad females shoud produce poop. Then the males will produce a white milly substance. Females don't.
Occassionally females will produce eggs, after the poop. But usually only if you are being TOO ROUGH with them.