Yes. if you had stood in the rain as soon as the game started, Boruto would have found like $7, which is enough to afford the snacks for Himawari on day 1. and if you did not do so then, you miss that scene. You cannot make it up later and just buy snacks any old time. You had to buy those snacks then... think of it like. there was a super special limited edition snack in the store then, and you missed your chance to buy it because it wasn't there later.
Just to see that one scene. But you have to play the game again in both love and hate routes to see all the games content. You can just make sure you get it on that play-through to unlock it.
I suggest you join the discord or go to the website in order to get the guides. it'll walk you through step by step the beginning of the game to get the Himawari fly incident scene.
Yoruichi has one 'secret scene' too that can only be unlocked during one of her quests and is possible to miss.
I suggest paying attention to what scenes you did not unlock in the galleries/replay. consider going to the discord and getting the guides.
Yoru's is one that looks a lot like the kitchen scene where she gets attacked by high lust boruto, but it's the version that can only be unlocked during the quest/moment where Obo is also there telling her to do what you tell her to. slightly extended, more options and not the same as the regular kitchen scene.
When the game first starts, on day 1. you get a 'tutorial' on secret scenes that tells you you need enough love or hatred to pick options, and then two options appear. The game is not kidding or messing around, both of those choices are actual secret scenes too, one for love, one for hatred.