Second season of . Mizuha, a high school second-year, is having the worst seventeenth birthday ever. She's missing her chance to get close to the older student she admires, and her parents didn't even remember that it's her birthday. Worst of all, there's a new and unknown infectious disease making the rounds, so all her club tournaments and school trips have been canceled.

She's convinced that she'll never have the dazzling youth that she's always dreamed of... but then her childhood friend, Mizuki, suddenly declares himself a candidate to be her boyfriend.

This is a school youth story about four childhood friends who grew up like family, one being the heroine, Nishino Mizuha, and the four boys she grew up with whom she sees as family.