The Summer Hikaru Died, Vol. 7 by Mokumokuren

Yoshiki and “Hikaru” learn from Tanaka that the only way to stop impurities from flooding the villages is to close the “holes” letting them through. The catch? Holes can only be closed from the other side—and once a living human crosses over, there’s no way back. With that in mind, “Hikaru” makes a daring proposition: seeing as he isn’t human, he can patch the hole and return using his connection with Yoshiki.

Meanwhile, Asako and Tanaka try an entirely different tactic—convincing an impurity to do the job for them!