From Chibi Manga:

Minako entered in the same high school as her nephew Shuu. And then she figured out that one of her classmate is the guy she loves: Takuma. She will have to make a choice between love and friendship.

Included in this manga is a two chapter short story called Sakura no Kioku in vol. 2:
Her graduation ceremony is approaching. Because she wanted something else, she decided to break up with her boyfriend, but...