完結[kanketsu] conclusion
完結文[kanketsubun] sentence
完済[kansai] full payment
完熟[kanjuku] completely ripe or mature
完遂[kansui] to accomplish

完成[kansei] complete
完成品[kanseihin] finished product
完全[kanzen] perfection
完全コピー[kanzenkopii] exact copy
完全主義者[kanzenshugisha] perfectionist

双璧[souheki] matchless things
完璧[kanpeki] perfect
完璧さ[kanpekisa] perfection

圭璧[keiheki] ritual jades worn by feudal lords in ancient China
パー璧[paapeki] perfect
完璧主義[kanpekishugi] perfectionism (psychology)