Hiking Shiratani Gorge on Yakushima

A few quick questions, for those who have done the hike:

1) Are sneakers sufficient for this hike? I generally prefer them for hours of walking, and don't tend to fuss about "ankle support," but I do have my hiking boots ready to go if needed. I worry they might feel too hot and heavy after ~5 hours of hiking, though.
2) Should we anticipate needing to step into water to cross, or are the river crossings usually dry, assuming there's not been excessive rain?
3) Are the tarp-style ponchos good enough for the usual rain? I'm worried my actual rain gear might be too hot.

We are planning to visit for our hike in about 2 weeks. So late-ish May.

Thanks in advance for your feedback. I appreciate your insight!

I’ve only been once, in the first week of June. It is supposed to be the beginning of rainy season, but we lucked out with sunny weather. You should be prepared for a lot of rain, however. While you don’t need hiking boots, hiking shoes would be perfect. You don’t have to worry about significant river crossings, but if it rains, hiking shoes will keep your feet dry better than running shoes. The rocks could be slippery and if it rains, it will be muddy. You might appreciate the traction of hiking shoes. As for rain gear, yes, not getting too hot is the big issue. It is a hot and humid place. Very light Goretex with pit-zips is what I would wear. I don’t have any experience with ponchos. If it’s cool and covers a lot of your legs, it might be fine.

For hot and rainy hikes I would recommend a “hiking” umbrella. They will keep you mostly dry without getting sweaty. Take the poncho in case it starts pouring.

For that hike sneakers are fine but you might get wet feet as there is often a lot of water on the trail. The river crossing is usually possible without getting your feet wet.

Thanks for the feedback! Based on what I'm hearing here, I'll probably bring my boots along but, if we luck out with dry(er) weather, may stick with wearing my sneakers.