Mikaeri wo Motomeru Athena-san

Ishida is a boy who lives by the motto: "Always do the right thing, without expecting anything in return." Starting high school, Ishida meets a blonde beauty, Athena Fujisaki, whose attitude is the complete opposite. She will do anything to help those in need — however, she's no pure-hearted do-gooder. She's a demanding girl who wants an equal return for every favor she does! A coming-of-age comedy about a well-meaning but chaotic girl whose goodwill goes off the rails, and the laid-back boy caught in her wake!!

(Source: Kodansha, translated)