Traveling during obon

I am arriving to Japan with the following itinerary (see below) I was worried a bit about obon and train tickets, what do you think

AUGUST:

3d- Arrive Osaka airport and overnight Osaka
4th- Daytrip to Koyasan and back to Osaka to sleep (I think this should be OK)
5th- Go to Miyajima and overnight there.
6th- Hiroshima, overnight in Hiroshima
7th- Yamaguchi, there's a festival and I already have booking in Yuda Onsen
8th- Onomichi, I pick last train via Okayama which arrives at 23:33 in Matsuyama city.
9th- Explore Matsuyama and overnight there.
10th- Pick first train to Kochi city, around 5-6 AM to arrive early.
11th- Kochi to Takamatsu
12th- Explore Naoshima and come back to Takamatsu
13th- Half day in Takamatsu and half in Tokushima to see AWA ODORI, come back with last Ltd Express from Tokushima to Takamatsu

14th- From Takamatsu to Kobe and overnight in Kobe
15th- Kobe to Nara, overnight in Kyoto
16th- Kyoto
17th- Explore Kyoto and pick 6 PM Limited Express from Osaka to Kii-Tanabe in Wakayama.
18th- Kumano Kodo hike
19th- Kumano Kodo hike
20th- Nachi falls and leave after lunch or afternoon back to Kyoto from Kii-Katsuura.
21st- Kyoto
22nd- Go to Tokyo early
23d to 27th- Stay in Tokyo.

So in terms of train booking do I have to be careful about something? Personally my MAIN CONCERNS are day 8 from Onomichi to Matsuyama via Okayama, 10th first train Kochi to Matsuyama, 11th Kochi to Takamatsu, 13th the last train of the day from Tokushima to Takamatsu, 17th the Ltd Express from Osaka to Kii Tanabe and the 20th the train from Kii-Katsuura after lunch, should I worry a lot? mainly because there's not a lot of frequency of those trains...what do you think?

I don't think you'll have many problems.

Most if you travel is west of Osaka. And they are short-ish trips, so have slightly slower alternatives if the faster trains are fully booked.

When Obon really starts you are already in Kansai (Kobec).
And no, I wouldnft be worried. Buy your train tickets when you first arrive and you should be fine.

Your itinerary to me seems to be too busy though, but then I am a very relaxed traveler.

I donft understand your day to Matsuyama though. Habe you looked into taking a ferry instead?

iYour itinerary to me seems to be too busy though, but then I am a very relaxed traveler.

I donft understand your day to Matsuyama though. Habe you looked into taking a ferry instead?

Yes it's a bit rush but I'm used to that. My day to Matsuyama is because from Onomichi to Matsuyama next morning would take 4 hours and I am thinking to get JR Pass so I can take a train like at 18 h and arrive at Matsuyama at night, sleep calmly and next day explore at the fullest, moreover my hotel is right next to Matsuyama station

From Onomichi to Matsuyama, the fastest (and cheapest) way is to take buses.

https://x.gd/V3mFT

For example:

Onomichi-ekimae 17:10 17:31 Mukaishima bus stop 17:35 18:29 Imabari-ekimae

From Imabari, take JR train to Matsuyama.

Imabari 18:47 19:23 Matsuyama

Coming back to this thread,

is it worth taking the Green car? I always use JR Pass Standard version and found it fine, only issue was back in 2018 when I had to go to Non Reserved car for Akita to Aomori which has very unfrequent trains.

Thanks

Wild guess, but I donft think the nation wide JRP can pay off. There might be a more regional one that covers Shikoku and Kansai to Hiroshima.

I personally have never taken green car although my previous company would have reimbursed it for business trips. The cars look quite similar. The only time I ever took green car was from Tokyo to Zushi or Kamakura for being able to sit.