Yes, when you publish on Steam, you can't have the game available at a cheaper price tag anywhere else.
I am not 100% sure about that but I think it includes demos, limited versions and that kind of stuff.
When I'll release it on Steam, I will more likely up the price tag of Summer Scent to match the standard for that kind of game (from $10 to $15 I believe).
I'll have to do some more research, but you're right. I should probably increase the price tag on Itch as soon as possible, to mitigate future problems. In combination with gifting Steam or Itch keys, that could do the trick.
A lot of things to think about!
Thank you!