Vocabulary consisting only from characters you are able to read

kanji kana meaning randomReload
空手 karate karatesport
空く aku to become vacantgodan, jlpt3, jlpt5, leda1, verb, vintrans
空っぽ karappo prázdnýleda1
sora skyjlpt5, leda1, shizen
空ける akeru vyprázdnit (láhev)ichidan, jlpt3, leda1, verb, vtrans