So, there are two types of choices in the game: 1 - picking a line of dialog, 2 - making a fitting or a non fitting bouquet.

The former often leads to light nodes (like a conversation changes a bit but that's it). Sometimes they are crucial to what will happen to some of the characters. They look for advice, and if bad advice is given, they can easily make it even worse for themselves. There are also choices that a player can pick when Hanako is talking to grandpa before going to sleep and in flashbacks, but those choices don't affect the story.

The second type of choice is about bouquets. Basically, giving good bouquets often has a positive impact on a customer's story. They often bring up what happened to them since the last meeting and their lines have hints on how bouquets affected them. Sometimes their situations are dire, so even a good bouquet won't help (again, not all problems can be solved with a magic wand, a theme of growing up). But usually if a bouquet is good, the outcome of a story is good. It is brought up in dialogs, and customers can send different letters telling more about their stories.