 He was adopted by the Katayama family at nineteen and adopted the name Sen Katayama, becoming the Katayama's "first son", after his birth mother was deserted by her husband.The adoption avoided Katayama's conscription and allowed him to continue his education.In his autobiography, "Jiden" (自伝), Katayama admitted that he was fortunate not to have been the first born in his birth family, as it saved him from some of the responsibilities that burdened some of his acquaintances.