On the other hand, at this time, Japanese society was in a period of great change, which was marked by the large circulation of coins in the economic field of the Song Dynasty and the frequent occurrence of economic activities among the samurai class, peasants, industrialists, merchants, and financiers. Corresponding to the prosperity of the society at that time, the Shogunate royal family did not hesitate to borrow money to survive in order to afford a luxurious life, and even mortgaged their own holdings and estates. The common peasants were exploited more brutally by the lords, and during the great famine of the Zhengjia period, robbers swarmed everywhere and evil parties ran rampant. This phenomenon was not a momentary phenomenon, but a reaction to the rapid progress of Japan under the leadership of the vigorous Kamakura samurai regime, and in the midst of a great wave of change, people were either swept away by the tide or fighting for their own future, completely unaware of the arrival of another, even greater wave that was sweeping the world.

However, it is not without people who see the world clearly. As early as the first year of Bunio (1260 AD), the founder of the Nichiren sect, Nichiren Venerable Master, keenly grasped the changes of the times, and in his book "The Treatise on the Establishment of the Shogunate", he predicted the prospect of invasion by other countries and civil strife in Japan, and persuaded the shogunate to change course and convert to the right path. These words of the Nichiren Master were obviously of no use to the Kamakura shogunate, which had become completely autocratic.

In response to the social conditions at the time, the shogunate issued an edict to suppress evil parties to improve public order, and at the same time, it explicitly protected the interests of the royal family, which was the pillar of the shogunate, at the expense of the interests of industrial and commercial owners and financiers. In such a turbulent social environment, the Kamakura shogunate had to assert the authority of the samurai regime in order to maintain the dominance of the Hojo regime. Because of this, it was impossible for the Kamakura shogunate to bow down easily in negotiations with the Mongols, otherwise the authority of the shogunate would collapse in an instant. Both Kublai Khan and Xin both believed in their military might, and they could not understand the hard-line attitude of the island nation of Japan, and their understanding of the turbulent and high-spirited social situation in Japan was very insufficient, and they did not have sufficient experience of Japan's determination to persist in the War of Resistance Against Japanese Aggression.

In the fifth year of the arrival of the first Mongol envoys in Japan (1268 AD), when the Japanese Imperial Court was still engaged in lengthy discussions, the shogunate had already issued a warning order to the imperial family in the western country. In the 8th year of Bunei (1271 AD), the royal family of the eastern province went to Kyushu one after another under the mobilization of the shogunate, and in February of the following year, the local imperial family of Kyushu began to patrol the coast in the Chikuzen and Hizen areas (foreign police fortification). At the same time, the imperial family in Kyushu strengthened their armaments on the one hand, and on the other hand, they also strengthened the suppression of the evil parties in the territory.

In October of the 9th year of Bunei (1272 AD), the shogunate began to investigate the number of lands in various prefectures, the domains they guarded, and the estates in order to grasp the military mobilization and economic power of each region, and to prepare for a full-scale war of resistance. At the same time, the investigation also suppressed the behavior of the royal family to buy and sell the territory to a certain extent.

Taking advantage of the war of resistance against the Mongols, Hojo not only seized the administrative power of the imperial court in the western country, but also adopted a strong policy of control within the shogunate and in the social and cultural fields. In that year, Tokimune of Hojo killed his half-brother Tokisuke Hojo, who showed signs of instability, and exiled Nichiren, who was critical of the shogunate, to Sado.

By suppressing the evil party, controlling and guarding them, suppressing and suppressing dissidents, and implementing a comprehensive vigilance, the Kamakura shogunate was determined to fight a thorough war of resistance from the very beginning.

Hojo Tokimune's tough attitude was intended to express the shogunate's determination to resolutely resist the war, and secondly, to suppress the sharp contradictions faced by the samurai regime since the invasion of foreign countries.

When the Yuan army invaded, the samurai of the imperial family in Kyushu actively participated in the war, although it was to defend their territory, but many samurai groups from the western and even eastern countries also fought bravely and went to Kyushu to participate in the war. Of course, the explanation for this positive attitude cannot be superficially prevaricated by the so-called truth of "defending the family and defending the country", and in fact this phenomenon is deeply related to the imperial family system of the Kamakura shogunate. The relationship between the samurai class, which was a member of the imperial family, and the Kamakura shogunate, which was the representative of the samurai regime, was not just a simple master-servant relationship, but the fundamental relationship between the shogunate and the samurai was actually based on "imperial grace" and "bongko". The shogunate awarded a title to a samurai based on their performance on the battlefield was called "goen", and in order to obtain it, the samurai had to faithfully fulfill his duty of "devotion to the public".

However, as for resisting the Mongol invasion, it was a purely defensive war, and it was not possible to confiscate the territory of the defeated and reward the samurai who fought bravely as in the previous Battle of Genpei and the Shoku War. The disappointment of the warriors who braved the rain of arrows and artillery of the Mongols to shoot their horses forward, and who died generously with a short sword in their hands and a bloody cavity shouted for their feats of war but could not receive the rewards they expected.

In addition, from the Kamakura period onwards, samurai families often adopted the system of inheritance by the eldest son in order to grow the family, and only the eldest son could inherit the territory of a clan, and the children of other families either gave up their status as samurai to participate in agricultural work, or groveled as a retainer of the eldest son, or only became a monk. The only way for those unwilling children to get ahead is to serve the shogunate and obtain the shogunate's royal grace in exchange for their own territory. But the war against foreign enemies blocked this only way, and the samurai class was deeply disappointed with the upper echelons of the shogunate.

As a result of this dissatisfaction, the samurai were pitted against each other, and the samurai in various regions fought for their territory. The samurai also developed a sense of distrust of the local guards who were in charge of direct command of the battlefield. For this reason, the shogunate issued a special order to protect the samurai against foreign invasions.

After the fall of Kyushu, the Kamakura shogunate used the excuse of foreign defense as an excuse to greatly change the protection of each country. Among them, the guardian of the Six Nations is the Hojo Ichi, the ruling power of the shogunate, and the other new guardians are also relatives close to the Hojo clan. During the Yuan invasion, the centralized rule of the Hojo clan had reached the point of being exposed, and the friction between the Hojo clan and the imperial family, who were the pillars of the Kamakura shogunate, continued to emerge, and this irreconcilable contradiction increasingly dragged the Kamakura shogunate into decline and foreshadowed the defeat of the war.

After the Yuan army occupied Kyushu, the Japanese army organized a naval army and launched two attacks on the Yuan army, both of which were easily defeated by Zhang Xi. Realizing the difference in the combat effectiveness of the two sides, the Japanese army no longer attacked, but began to build fortifications with all its might, waiting for the attack of the Yuan army.