However, when he became aware of the intent of Hideyoshi to clearly conquer during the Imjin War, he also decided to return to Satsuma with Guoan GUO, recorded details of the situation then in Japan and sent the records to Ming China by pretending to send documents to fellow Satsuma resident Kino SHU.
しかし、秀吉の起こした「文禄・慶長の役」の目的が明の征服と知ると、同じく薩摩に帰化していた郭国安と共に、明へ日本国内の事情などを記した密書を、同郷である朱均旺に託し送っている。