The worst birthday of your life becomes the moment everything changes. Mizuha's drowning in the specific cruelty of being seventeen in July 2020, tournaments canceled, crushes impossible, parents checked out, when the person who was always just there suddenly isn't anymore. That's when you realize he was never just a childhood friend, and the show knows exactly how to make you feel that realization hit the same way she does.

Mizuha's seventeenth birthday, on July 1, 2020, turns out to be the worst one yet. Her crush remains out of reach, her parents forgot entirely, and a spreading illness cancels her club tournaments and school trips. The dazzling youth she imagined for herself feels impossibly distant. Then Mizuki, a childhood friend she has known her whole life, suddenly declares himself a candidate to be her boyfriend. Having never been in love, she brushes it off, but he is serious about winning her over. Around them are three other boys she grew up with like family, and they seem to have feelings for her as well. Mizuha has to sort out her own heart without breaking apart the close group she treasures. What happens when you stop seeing someone as family and start seeing them as a possibility?