 In 1582 he attacked the Arima clan and Arima Harunobu decided to ask the help of Shimazu Yoshihisa.Yoshihisa sent an army in December of that year but not much progress was made until 1584 when the army was reorganized and commanded by the able Shimazu Iehisa, younger brother of Yoshihisa.The allies put Shimabara under siege and Takanobu marched to relieve the castle with his main army.