The Summer Hikaru Died, Vol. 4

Two boys grew up together in a certain villageYoshiki and Hikaru. One day, Yoshiki became sure that Hikaru was no longer himself. He resolved to accept the new Hikaru, whatever happened to his friend. But now hes decided to research the history of Nounuki-sama and Kubitachi to understand what this creature truly is. The situation evolves unpredictably, outside the boys control. Who will make the next move, and what will they find?