Saya is a high school model and a huge fan of Ria. One day, she feels something reminiscent of Ria in a girl she passes by on the street. The girl she meets by chance, Mari, claims to be Ria's twin sister, but unlike Ria, she has a more subdued appearance and a modest aura. With the hope of getting closer to Ria, Saya tries to befriend Mari, but she gradually finds herself drawn to the shy and cute Mari... The title work "Kira Kira" is included, along with the series of short stories "Beloved Person," which depicts the bittersweet love from adolescence to adulthood, making this the author's heartfelt second Yurihime comic.