事前に必要[jizennihitsuyou] prerequisite
生者必滅[shoujahitsumetsu] All living things must die
絶対必要[zettaihitsuyou] absolutely necessary
必ず[kanarazu] always
必ずしも[kanarazushimo] (not) always

必ずや[kanarazuya] certainly
必携[hikkei] handbook
必見[hikken] worth seeing
必殺[hissatsu] certain kill
必死に[hisshini] frantically