Shinzei rejected Yoshitomo's offer of marriage, saying that his son was a scholar and a samurai family was not right for him to marry into, but then he contracted a marriage with the Taira clan, which was also a samurai family ("Gukansho").
『愚管抄』の記述を史料に、義朝の縁組の申し入れに対して信西が「我が子は学者であるので、武門の家の聟には相応しくない」と拒否しながら、同じ武家である平家と縁組したことが書かれている。