Sara and Mei is the Omake of Volume 4 of the Citrus manga. It was released on July 18th, 2015.
Sara and Mei
This takes place right after Mei and Yuzu confess each others true feeling in front of the love shrine, Mei and Sara have a heart to heart talk and Mei appologises about using Sara. Sara explains that it is ok and that she is happy that Mei and yuzu are happy, Though she only forgave Mei after she promised to hold hands with Yuzu all the way back to the hotel.