Miageru ni wa Chika Sugiru, Hanarete Kurenai Takase-san

After Mizuki Shimono was rejected by a girl he liked because of his short stature, he lost all confidence and his personality turned introverted. But for some reason, a girl was bothering him. Nao Takase was kind, popular, and tall. Just being in the same room made him feel inferior. But even though she seemed mature and confident, she was also strangely innocent in other ways, naming stuffed animals and hugging them without worrying about what others think. She shouldn't want anything to do with a guy like him. But when Mizuki looked up at her, her true face seemed oh so close. This is a coming-of-age love comedy of two opposites becoming woven together. Their height difference is 20 centimeters, but the distance between them is zero.

(Source: GA Bunko, translated)