Citrus

is a Japanese yuri manga series written and illustrated by Saburouta. It has been serialized in Ichijinsha's Comic Yuri Hime since November 17, 2012. Its first volume has been licensed by Seven Seas Entertainment for a printed release in North America on December 16, 2014. An anime adaptation by Passione will premiere on January 6, 2018.

Plot
Yuzu, a fashionable teenager, transfers to a quaint and conservative girl's school after her mother remarries. She encounters Mei, the beautiful student council president and grows to dislike her stern attitude. At the end of the day, Yuzu comes home only to meet Mei again-- she's her new step sister. The girls struggle with their relationships and battle their feelings of love and hate.

Official

 * Offical anime site

Other Sources

 * Wikipedia