Matsu Matsuzaka (まつざか 松 Matsuzaka Matsu) is Ume's eldest sister. She is 28 years old. Like her sister, she is also seeking for a man to form a relationship and eventually marry. Often, when news comes of Ume going on a date or participating in a matchmaking ceremony, Matsu and her other sister, Take, would interfere to win that man's affections, leading to the three sisters fighting over him and eventually ends up with the man she is interested in escaping from the sisters. A similar situation transpired when Ume started dating Tokurou Gyouda.
Matsu means pine in Japanese. The names of the three sisters refer to pine, bamboo and plum (松竹梅), three plants, being resistant to cold, are known in the East Asian tradition as the three friends of winter.