There are more than one artist who use "J" as their name. 1. Jun Onose (Born on August 12, 1970 in Hadano, Kanagawa, Japan), referred to by his stage name J, is a Japanese musician, singer-songwriter and record producer. He is best known as bassist, co-founder and leader of the rock band LUNA SEA. After the group disbanded in 2000 he focused on his solo career, for which he performs lead vocals and bass. He has recently rejoined Luna Sea as they reunited in August 2010.