無冠の帝王

むかんのていおう

expression, noun

person who has not won any major awards or titles despite being the best in a particular field, uncrowned king

person who wields power without holding an official rank or title

journalist (esp. newspaper journalist)

無	nothingness, none, ain't, nothing, nil, not
冠	crown, best, peerless
帝	sovereign, the emperor, god, creator
王	king, rule, magnate