A Star Brighter Than the Sun (NaN)

Sae and Kōki have been friends since childhood. One fateful day at the end of middle school, she has a revelation: Kōki has grown up! Now they're in high school, and she has another revelation: she has feelings for Kōki! But Sae isn't the only girl who does… The question is, who does Kōki have feelings for?!