Majo Matsu is a resident of Witch Frog Town in the Witch World.
As a witch, Majo Matsu bronze colored hair with brown eyes. Her spherical earrings are magenta colored and larger than average earrings worn by most witches.
As a witch frog, Majo Matsu has Persian green colored skin and a wide head with two curled hair strands on each side.
Her Crystal Ball is blue and shaped like a sagittate leaf.
Like many of the other residents of Witch Frog Town, Majo Matsu is friendly and loves to party.
Some time prior to the series, Majo Matsu's identity as a witch was exposed by an unknown human, causing her to transform into a Witch Frog as a result of the curse cast by the former queen's predecessor. She has since then moved to Witch Frog Town in the Witch World.
During a powerful storm in the Witch World, Majo Matsu and her fellow Witch Frogs were blown through a doorway that connects the Witch World to the Human World. Landing in Onpu Segawa's office, they proceeded to have a wild party, drinking alcohol and dancing.
The next morning the Ojamajos brought Majo Matsu and the remaining witch frogs that were in Onpu's office back to Mahou-Dou so they could reunite with Majo Ume, who had wandered off there hours earlier. The witch frogs then refused to return to the Witch World until they got in some sightseeing of the Human World with the Ojamajos as their escorts.
Sometime later, the Ojamajos take their Level 3 exam and the first door that Doremi enters takes her to Witch Frog Town. Majo Matsu and the other residents invite her into one of their homes and serve her manjuu and tea. After a short while, Doremi realizes that she's in the middle of an exam and can't stay, so Majo Matsu and the other frogs send a box of manjuu with Doremi as a souvenir.
Motto! Ojamajo Doremi
The Ojamajo girls visit Majo Ume, Majo Matsu, and Majo Take in their home with the intent of inquiring Majo Leed about the cancellation of their Patisserie exam. Majo Ume shoves a manjuu into Momoko's mouth, saying that Witch Frog Manjuu is the village's specialty and offers all of their overstock to the girls. Ume then explains that as delicious as they are, the once popular manjuu hasn't been selling lately due to customers getting tired eating them all the time.
Later at the town meeting, Majo Leed makes a prejudicial comment towards the Ojamajos due to them being Japanese humans, angering Momoko to vocally question Leed's authority status. Majo Ume tells Momoko that she's being rude to the mayor, to which Momoko told her to shut up, causing Matsu and the other witch frogs to cower before Momoko's straightforwardness to confront Majo Leed.
After the town meeting, the girls sit down with the witch frogs again to discuss Majo Leed. Ume explains that Majo Leed brought Japanese influence to the town while building it. The girls decide to help the witch frogs by creating a new specialty sweet for the village to sell. Matsu and her fellow residents offer to help the girls in creating the sweet, wanting to contribute. Upon finishing the various flavors of uiro, Ume comments that the green one resembles Take, who retorts that it just means it looks like Ume as well, Matsu adding that it's because all of the witch frogs look the same.
Ojamajo Doremi Dokkaan!
After Majo Tourbillon was awakened from her millennium-long slumber, she lifted the Curse of Witch Frogs, reverting all witches who fell victim to the curse, including Majo Matsu, back to their true forms.