Yunyun is a beautiful young girl with crimson-colored eyes and mid-length dark brown hair tied into two twin-tails that lie on her shoulders. Aside from being taller and more buxom, she is very similar in appearance to Megumin.
Yunyun usually wears black robes and a cloak, similar in design to Megumin’s. She wields a silver staff and keeps a short sword sheathed around her waist. Underneath the cloak, she wears a low-cut blouse and ultra-short pink miniskirts. She wears the revealing outfit, however, not because of personal preference, but because someone told (lied to) her it is a good way to make friends.
Not visible on her character, she also has a barcode on her inner thigh.
Yunyun has a determined, caring, and gentle personality. She is also quite shy and quick to blush. She is not always honest with her feelings. While very intelligent, she often takes other people's words too literally. Aside from Megumin, she never confronts others, even when she knows they have lied to her. She is the only Crimson Demon to not display eccentric behavior, leading her to hold mixed feelings towards her own clan. However, it is hinted that Yunyun has chuunibyou tendencies like the others, such as how she worries about other people's opinions about her.
Due to being unable to make friends, Yunyun gets excited easily when someone approaches her to ask her to join their party. Unfortunately, as a Crimson Demon, her eyes glow bright red when excited, which has led to her scaring off adventures who wanted to add her to their party as Yunyun would get excited and her eyes would glow brightly the moment someone read her party request at the guild's bulletin board.
Yunyun is also quite pessimistic, always thinking that people assume the worst of her as a consequence of the social ostracizing she experienced growing up in the Crimson Demon Village. Known as the endeared "solo hunting super rookie arch wizard," to the various adventurers around Axel, she is famous around town for rescuing beginning adventurers stuck in a pinch. However, instead of sticking around to receive thanks, she runs off as soon as she saves them, misreading the situation and crying "sorry for doing something so unnecessary!" As a result of this, it accomplishes the opposite of her desire to make friends as rumors that "there is no doubt she hates associating with people" have spread throughout the Adventurer's Guild, causing the inhabitants of the city to ignore her to "return the favor."
Yunyun is the daughter of the Crimson Demon Village Chief. She and Megumin were classmates in their village's magic academy. Megumin was always the top student, while she was second. Yunyun claimed she would go on a journey to train herself until she could use top tier magic.
Later, after shenanigans with Dust's party, she makes her first "friend" in Vanir in the latter's spinoff, though only a few lines later, his thoughts show it to be a plot to acquire a source of "wagerless labor" after Wiz used up the eris that their shop had acquired from the sale of Kazuma's developed goods. This does, however, lead to Yunyun and Wiz developing a close relationship as time passes.
Due to Yunyun being a loner for almost her entire life, she is able to almost completely conceal her presence from others, if she has even the smallest of furniture in front of her (for example a bookcase, a table, or just a shopping shelf).
- Intermediate Magic: Yunyun was forced to learned intermediate magic under pressure to save both herself and Megumin from monsters.
- Advanced Magic: After putting in a great deal of work, she was finally able to learn the advanced magic synonymous with her village.
- Light of Saber: A move that makes a slash of light that cuts monsters in half and can deal a fatal blow.
- Teleport: An ability allows Yunyun to save check points for where she can teleport to and from and allows her to teleport away from danger.
- Cursed Lightning: A lighting strike that electrocutes the enemy
- She celebrates her own birthday by herself and even gives presents and sets up a party where she is the only person there.
- Konosuba Fantastic Days' Twitter account revealed that Yunyun's birthday is on February 29th.
- She often plays two player games by herself, such as chess or checkers, and takes turns switching seats to act as the second player
- She hasn't been able to join any party due to her shyness to confront and ask people if she can join and will often run away when a party she saves tries to thank her or ask her to join their group
- She once asked Kazuma to have her child.
- She has a barcode birthmark on her inner thigh very close to her crotch.
- [After Kazuma invites her to dinner at the mansion] “C-Can I?! But having dinner together feels like a family affair, so I feel like I shouldn’t be here, actually in the first place visiting this late is my fault, so, sorry, Kazuma-san, but showing up at a friend’s house uninvited and joining them for dinner is, ah, no, it’s not like I dislike it, actually I’m really happy that you invited me and-”
- "I want to have Kazuma-san’s children"