On Google Map, Hongu Taisha (本宮大社) and Koyasan seem very close but getting from one place to the other is non-trivial.
Day 5: 10:32 Nara Kotsu Bus from Gojo arrives at Watarase-Onsen (渡瀬温泉) at 2:42, check out Yunomine Onsen (湯峰温泉) “an integral part of the over 1000 year old Kumano pilgrimage tradition. Pilgrims performed hot water purification rituals in these piping hot mineral waters after their long journey in preparation to worship at Kumano Hongu Taisha”
Day 6: 8:21 Ryujin Bus from Watarase-Onsen to Nonaka-no-Ipposugi (野中の一方杉), walk 6.5 hours to Hongu Taisha, take shuttle to Watarase-Onsen
Day 8: 8:21 Ryujin Bus arrive at Kii Tanabe at 10:15, 10:41 JR train arrive at Wakayama Station at 11:48, 12:09 train arrive at Sanjo Station at 1:34
My original plan was to use Yamato Transport to ship our luggage from Koyasan to Watarase-Onsen and stay at a couple different places along the trail but he doesn’t want to do shared bathrooms. The new plan involves taking the bus from Watarase-Onsen to different places along the trail but I think it’s worth it because Watarase-Onsen has a super nice private bath.
Here is the original plan.
Day 5: 9:55 bus arrives at Kurisugawa (栗栖川) at 1:25, walk 30 minutes to Kiri-no-Sato Takahara Lodge
Day 6: Walk six hours from Takijiri to Nonaka-no-Ipposugi, check into Irorian Minshuku
Day 7: Walk 6.5 hours from Nonaka-no-Ipposugi to Hongu Taisha, take shuttle to Watarase-Onsen