I'll Be Entangled In Thoughts, With You Someday.

In second year of middle school, Musubu Shiomi is just living an ordinary life. But on the graduation day of her Senpai, her (former) childhood friend Shizu-chan she estranged from, she is asked to take a picture together with him. “I’m going to Kitakou High School...”

"I will also go to Kitakou High School!” Musubu fulfills her promise she kept for an entire year and mages to swiftly enroll at the same high school as Shizu-chan, but…

(Source: Ciao Plus, translated)