Premieres sometime this year. Check out the ANN article for additional information. Synopsis for the source manga from AniList:

Sakue Iwata is a big girl self-conscious about her height. Her childhood friend Mitsuki, who was just a little boy when they were young, has grown into a handsome young man. She thought they had drifted far apart, but they were reunited at the final sports festival of junior high school…? A fresh and exciting story full of sparkle!