Oh a nice start. We get these little glimpses into what makes Kurisu tick. She coasted in high school, but she doesn't get the same recognition at work. Then she gets rizzed up and everything feels new and exciting again! Yayoi feels like a fairy-godmother who fixes all her problems.
I want to infer that she's still coasting as an adult, and that's why her work isn't going well. I won't die on this hill since nothing like that has been shown. But it makes sense as a character; It's the talented teen to burn-out adult trope: She is struggling to deal with things that don't come easily to her, she never learned how. It makes sense why she fell into her hook-up with Yayoi so easily, and started to act out when she found out it's more complicated than she thought. She's also insecure because her job keeps telling her she isn't good enough.
I'm hoping for a personal growth type Yuri and not a toxic drama type.