あらためたそうだ
aratameta sōda

Ichidan Verb
Evidential Auxiliary

Expresses hearsay about a past event ("I heard that...") of 改める

1. It is said that [someone] revised [something].; It is said that [someone] reconsidered [something].; It is said that [someone] changed [something].

Past/Perfective
Hearsay Evidence