The First Book by Monika Xu

(Crossover anime world) (Two heroines) (Subtle emotions) (The complete Yukinoshita family, maybe?) Sakurai Aoyu enters high school, looking forward to starting a new school life with his childhood friend, Yukinoshita Yukino. But the gears of fate start spinning wildly when he becomes desk mates with Kato Megumi, a classmate so inconspicuous she barely seems to exist. The first task he receives after being bound to the System is to say an embarrassingly romantic “confession” to Kato Megumi in front of Yukinoshita Yukino! Caught between his aloof childhood friend and the calm, girl-next-door heroine, Sakurai Aoyu's chaotic and lively high school life begins!