か

This looks like someone doing a karate kick. It sounds like “ka”, the beginning of “karate”.

き

This character looks like a key and sounds like “key”.

く

Imagine that this character is the open beak of a bird saying “koo”. It makes the same sound.

け

This character looks like a barrel, or keg. It’s spelled “ke” like the first two letters in “keg”.

こ

This character looks like the outsides of a round coin. It’s spelled “ko” and sounds like the first two letters in “coin”.