I should also include dialogue that reflects Hinata's character—energetic and supportive. The protagonist's internal monologue can show his emotional change. Need to be careful with the tone and not make it too cheesy. Maybe end with a hopeful note for their future.
Check if there are any potential issues. The story shouldn't conflict with Love Live! canon too much. Since Hinata is already in a group, her having a boyfriend isn't established, but for a fanfic, it's acceptable. Also, ensure that the ecchi elements are appropriate and not overly explicit, keeping it as a gentle rom-com style. Natsuiro Hinata Ecchi Na Kanojo To Tokeau Kokoro
“Closer than usual?” she finished, her voice soft. “Yeah, I noticed.” I should also include dialogue that reflects Hinata's
“Tatsuya,” she breathed, “ I think I’ve liked you a lot longer than I admit .” Maybe end with a hopeful note for their future