Saeki San to, Hitotsu Yane No kaI'll Have Sherbet! 1 (Famitsu Bunko) [Light Novel]

[Machine Translation] In the spring of his second year of high school, Kyoushi Yumizuki was supposed to start living alone, but due to a mistake by the real estate agency, he ended up living with a girl one year younger than him named Kirika Saeki. She was always trying to get close to me, and I kept putting up a small resistance, but to my surprise, she also went to the same high school as me! I am pushed around by her both at school and at home. The always calm Yumizuki-kun and the extraordinarily beautiful but a little bit H-money Saeki-san start their cohabitation and school love comedy.

高校二年生の春、ひとり暮らしを始めるはずだった僕こと弓月恭嗣は、何の冗談か不動産屋の手違いで、ひとつ年下の佐伯貴理華さんなる女の子と同居するはめになってしまった。やたらと距離を縮めてきたがる彼女に、ささやかな抵抗を続ける僕だったが、なんと彼女も同じ高校!学校でも家でも彼女に振り回される日々が始まって―。常に冷静な弓月くんと、とびきりの美少女なのにちょっとHな佐伯さんが繰り広げる同棲&学園ラブ・コメディ、開幕です。