Negative Boy Nega-kun and Positive Girl Posi-chan

Nega Shouya and Hoshi Sayaka are high school classmates. Nega is tremendously pessimistic, while Hoshi is optimistic, both to a fault. They also happen to be deeply in love with each other, but they completely misread each other's cues, him erring by defect, and her erring by excess. The fundamental law of magnetism states that opposites attract, and these two starkly different young lovers are not the exception!

(Source: Kadokawa, translated)

Note: Includes 5 extra chapters.