Su Yao is 175 centimeters tall and painfully aware of it. Liu Xi is 160 centimeters tall, close enough that Su Yao never quite knows where to place her hands, her gaze, or her heart. This height difference between two high school girls becomes the quiet axis around which their entire relationship turns.

It begins with an excuse too small to question. Liu Xi asks, Can I borrow your textbook? One borrowed textbook becomes another. Soon they are sharing a desk, Liu Xi gently tugging at Su Yao's sleeve, offering a smile warm enough to linger. Su Yao tells herself she is only being thoughtful, only being kind. But every time Liu Xi tilts her head and looks up, something inside Su Yao falters.

The story unfolds in a contemporary Japanese high school setting, though the characters have Chinese names, reflecting the creator Taa RO's background. The series has been serialized on the Japanese platform Pixiv since December 2020, with seven chapters released as of early 2026. The narrative follows the aching sweetness of first love and the fragile courage required to reach for it, focusing on small, intimate moments rather than dramatic declarations. A shared glance across a classroom, the brush of fingers when passing notes, the hesitation before speaking a feeling aloud. These accumulated details build a portrait of unspoken longing and the desperate wish to be closer to someone already within arm's reach.

The title numbers, 175160, directly reference the protagonists' heights, a constant visual reminder of the gentle distance between them. As Su Yao grows more aware of her feelings, she must navigate the boundary between thoughtfulness and something deeper, questioning whether Liu Xi's requests for her textbook are simply practical or quietly intentional.