In Tsukumono Village, Sister Kaku handed over the carefully modified Chihiki Stone fragments, which she had worked on for two days, to Kamiyagawa, with some additional instructions:
"After you head to Yomotsu Hirasaka, this fragment of Chihiki Stone will remain in place, and I will keep it safe. If you encounter any troubles that you cannot solve, you can teleport back using the Chihiki Stone from Hirazaka."
"Don't worry about the teleportation pathway; I have redesigned it all. The piece of Chihiki Stone we hold has been modified by the Takamagahara Passage Token, so only you can activate this path."
Perhaps Sister Kaku had recently mastered some IT skills?
It seemed she handled these artifacts, requiring complex design instructions like the Chihiki Stone fragments, with increasing ease.
Kamiyagawa: "Wait a minute, is there no limit to how many times I can use the Chihiki Stone?"
"None."
"Understood. Then I'll test the effect of round trips first."
