Girigiri Saegiru Katagiri-san

Okada-kun is a guy who's at the bottom of the school caste. His only reason for living is to someday see his classmate's large boobs. However, whenever he so much as makes an attempt, Katagiri, his flat-chested classmate, is delighted to block his view, relishing in his look of despair. Just where will their battle without honor take them?!

(Source: Kadokawa, translated)