Watatsuki no Yorihime is a leader of the moon emissaries, who are tasked with defending the Lunar Capital and keeping an eye on Earth. She has a no-nonsense personality, shown by her strict training of the moon rabbits and her own disciplined practice regime.

Yorihime's ability to summon divine spirits allows her to fight while housing various divine spirits in her body. The stronger the god she summons, the stronger she becomes. Apparently, she gave Reimu some training when Reimu and the others visited the moon.

Peach trees grow in Yorihime and Toyohime's garden. Yorihime was planning to eat a certain peach with her sister once it had ripened, but when she went to check on it, it had disappeared. She decided to keep watch over the peach trees in order to find the culprit...

While Yorihime was keeping a lookout for the culprit... she noticed a hand reaching toward a peach. She rushed over to find Toyohime stretching her hand out from the window. Toyohime ignored her sister's scolding and offered her a peach too. Yorihime still had plenty more that she wanted to say, but she fell silent and dug into the peaches along with her sister.

Yorihime knows that Toyohime and Reisen often visit Gensokyo. She uses the excuse of having to bring them back to go and visit Eirin. Perhaps Toyohime continues to visit Gensokyo because she noticed this and wants to help her little sister, who struggles to admit her true feelings.