Soji Arai was born in Niigata, Japan. After graduating from Waseda University, one of the top private institutions of higher education in Japan, he began acting with the Bungakuza theater company. In 2002, he made a major impact on the Tokyo theater world with his starring role of Max in Bent directed by Robert Allan Ackerman. Soji also starred in many other plays including the multi-theater-awarded production of Angels in America, Desire Under the Elms, Three Sisters, Blood Wedding, Balm in Gilead and the world premiers of Strangers on a Train and The Roman Spring of Mrs. Stone. In 2009 he was introduced to world wide audiences as Toshi, Brittany Murphy's love interest in "The Ramen Girl". In 2013, Soji moved to Los Angeles to continue his American career.