In the article of May 19, 1185 of "Azuma Kagami" (The Mirror of the East), there is described a story that Aritsuna pillaged a lot of shoen-koryo (public lands and private estates) by saying he was Yoshitsune's son-in-law; accordingly, Aritsuna is considered to have been Yoshitsune's son-in-law.
『吾妻鏡』の元暦2年（1185年）5月19日条に、有綱が義経の聟であると称して多くの荘園公領を掠め取っているとの記録がある事から、有綱は義経の女婿とされている。