Hinoe castle, which served as the feudal lord Arima Harunobu’s headquarters, was a mountain castle located in the southern part of the Shimabara peninsula. Such mountain castles were characteristic during medieval times. In the neighbouring Saga, the zealous Buddhist feudal lord Ryūzōji Takanobu was trying to increase his power, and frequently attacked the Arima clan.

After Toyotomi Hideyoshi had unified the whole country, he set his sights on attacking the Korean peninsula. Feudal lords from many different places gathered in Hizen Nagoya castle, and Hideyoshi had castles built in Iki and Tsushima as footholds. The stone wall fortification technique that was used at this time was later used again in the construction of Hara castle.

Gold-leafed “toribusama” roof tiles which have the Tomoe family crest on have been discovered in the ruins of Hinoe castle. The gold-leaf has been applied to the corrugated part where the family crest is. These same roof tiles have also been discovered in the remains of castles and palaces belonging to Oda Nobunaga and his family clan, as well as in those belonging to retainers of Toyotomi Hideyoshi (whose master was Nobunaga). Many have also been found in Jurakudai (a palace in Kyoto). These discoveries suggest that the Arima clan was deeply connected with the centre of political power at that time.