Boku to Kimi to de Niji ni Naru

Because she loved the word "wisdom," Rui hated the words "waste" and "fuzzy." One day, a guy named Shou appeared in her life. Thanks to that encounter, Rui will suddenly change... And that's the beginning of a "rainbow school daze" between that super dry girl and that careless guy.

(Source: Chibi Manga Scanlations)

Included one-shot:
Volume 1: Kimi no Tonari de Seishunchuu.: Tokubetsu Bangai-hen