An opinion is widely held that Sokei TANAKA who was the father of the second head of the family, Jokei RAKU was given a seal with the engraved character 'Raku' taken from the name of Jurakudai from Hideyoshi TOYOTOMI, and he began to use the seal and called his Yago (family name) Raku.
二代目・楽常慶の父、田中宗慶が豊臣秀吉より聚楽第からとった樂の印章を賜り、これを用いるとともに家号にしたことから楽焼となった、との説が広く知られる。