Centuries after the devastating war against the Nokkers in Renril, the world has changed beyond recognition. Thanks to Fushi's long efforts during his extended slumber, a modern civilization has emerged where he and all living beings can coexist in harmony. Upon waking from his rest, Fushi is eager to explore this new era and reunite with his lost companions.
During his travels, Fushi encounters Yuuki Aoki, an enthusiastic middle school student, who warmly welcomes him and his friends into his home. As the group settles into their new surroundings and learns the intricacies of contemporary life, Fushi meets Mizuha, one of Yuuki's friends, whose appearance reminds him of someone from his past.
Mizuha is revealed to be a descendant of the Guardians, a dedicated lineage entrusted with protecting Fushi. Like those before her, she forms a deep connection with Fushi, finding purpose in her bond with him. However, as Mizuha grows closer to Fushi, strange events begin occurring around her, signaling that beneath the surface of this seemingly perfect world lie hidden problems.