悪友[akuyuu] undesirable friend
畏友[iyuu] one's esteemed friend
益友[ekiyuu] good friend
学友[gakuyuu] school friend
級友[kyuuyuu] classmate

旧友[kyuuyuu] crony
血友病[ketsuyuubyou] haemophilia
交友[kouyuu] friend
交友関係[kouyuukankei] one's relationships
校友[kouyuu] schoolmate

益金[ekikin] profit
益虫[ekichuu] useful insect
益鳥[ekichou] beneficial bird
益友[ekiyuu] good friend
過剰利益[kajourieki] excess profit

共益[kyoueki] common profit
共益費[kyouekihi] monthly fee for common areas of an apartment building (lighting, etc.)
権益[keneki] (one's) interests
公益[koueki] public
公益事業[kouekijigyou] public utilities