I really like the way the romance is handle here, they don't accidentally hold hands and then get embarrassed like in a normal romcom, they just do it. And Yamada is great, she know what she wants and even if Ishikawa struggles with his own fellings he also know he loves her.
clearly, 1000000% they are not dating and don't like each other at all. it's very clear, that holding of hands was just replicating what a dog should do and nothing more whatsover.