Who is the person who "awakened" Masato by kissing him?!

A kiss that was forced, yet somehow── seemed to be longing.
It was only then that I realized what was happening when I saw ××'s expression.
──Which side is “above” now?
As the shadows of other rivals begin to appear, their heavy emotions become even more entangled.
Meanwhile, a new high school girl, Shiori, a fresh literary girl who Masato tutors, joins the fight.
In fact, her true face was that of a gloomy otaku who was obsessed with Masato… …?!
Who was the one who gave Masato the "awakening" kiss that shattered his unconscious side, which took "being kind to others" for granted?!
The second installment of the heroine derby spanning all generations, from middle school girls, high school girls, college girls, and even office ladies!