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

愛書[aisho] great love of books
愛読書[aidokusho] favourite book
悪書[akusho] harmful book
案内書[annaisho] guidebook
移動図書館[idoutoshokan] mobile library

遺言書[yuigonsho] testament
遺書[isho] note left by dead person
医書[isho] medical book
一つ書き[hitotsugaki] an item
一書[issho] one letter

会社概要[kaishagaiyou] company overview
概要[gaiyou] outline
肝要[kanyou] essential
紀要[kiyou] bulletin
強要[kyouyou] coercion

緊要[kinyou] momentous
緊要地形[kinyouchikei] key terrain
公教要理[koukyouyouri] Catholic catechism
構成要素[kouseiyouso] components
綱要[kouyou] elements

異類[irui] varieties
一類[ichirui] same kind
円虫類[enchuurui] round worms
塩類[enrui] salts
塩類溶液[enruiyoueki] saline

貝類[kairui] shellfish
柑橘類[kankitsurui] citrus fruits
希土類[kidorui] rare earth
魚貝類[gyokairui] marine products
魚類[gyorui] fish