Under the pretense of "going home," Tomoharu went back and forth from the eastern provinces, reporting to Hideyoshi on the movements and circumstances of the eastern daimyo (regional lords), engaging in what could well be described as spying.
帰郷と称して東国に出入りし、東国大名の動静を秀吉に伝える、諜報活動いわゆるスパイ的行動も行っていた。