When his elder brother, who was a joza (the highest rank of bokan), died suddenly in 1549, Shinrai SHIMOTSUMA was appointed as a proxy of joza for his elder brother's young sons, Raiso SHIMOTSUMA and Raigei SHIMOTSUMA, until they came of age.
1549年、坊官の最高位である上座の位にあった兄が急死すると、その子供である下間頼総・下間頼芸兄弟が幼かったために、成人までの間上座の代行を命じられる。