Onomichi in 6-7 hours doable?

Hello,

my plan is to start around 10:30 AM and visit Senkoji and the temple walk, cat alley, the arcade shopping district and eat some Onomichi ramen?

6-7 h are enough? Or I will need much more time? I need to pick 18:10 train to Okayama.

You can. It's not a huge place. I do love it there