The land of Karasun has an incredible power to attract monsters. Any monster that approaches there will gain powerful power and rapidly evolve and become stronger. When he was young, Yoshimori sympathized with a monster and caused it to change. At the critical moment, Shi Yin saved him, but was seriously injured. Yoshimori blamed himself very much and made up his mind to become stronger and protect Shi Yin. However, the dangers that the barrier master faces are far from as simple as he thought...