Sera and Serena (ムー＆スー, Mu & Su) are characters in Rune Factory 2: A Fantasy Harvest Moon.
These twins are opposites: one loves going outdoors, while the other likes staying inside and reading. They still get along very well, though, and often finish each others' sentences.
Sera and Serena dress similarly, but there are small differences. They both have blue eyes and their father's slivery-pink hair, but Sera parts her hair on the left, while Serena parts hers on the right. They both wear a teal scarf and a yellow-and-white tunic with no stockings, but Sera's tunic is long and white with yellow sleeves that cover her hands, while Serena's has no yellow on the sleeves, and is a yellow tunic with a white tabard and belt. Lastly, Sera wears sandals while Serena wears boots.
In dialogue, Sera is always on the left, while Serena is on the right.
Sera and Serena are Ray's daughters and Natalie's granddaughters. If Kyle did not marry her, Rosalind is their mother, Max is their uncle, and Herman is their maternal grandfather. They get along with everyone in class, but mostly play with each other.
Sera and Serena profess a desire to be friends with Aaron and Aria as soon as they meet. They frequently post bulletin board requests asking to play games with them. They both fully support Aaron and Aria in their quest to find out what happened to Kyle.
They are mock wedding candidates for Aaron and Aria, but they don't really understand what a wedding is. Even though they are two different people, they act as if they are one, in terms of gift-giving, so only one gift is needed to raise their LP.
The twins share taste in gifts. They like a wide variety of foods, with no apparent trends in ingredients or flavors. They dislike Sardine Sashimi, but like plain Sardines.
Serena: "Thanks! I love this!"
Sera: "You're giving us this?"
Serena: "Sorry, I don't like this very much."
They live upstairs in the clinic.