Alya Césaire

Alya is Marinette's best friend and a student at Collège Françoise Dupont. She is also the sole admin of the Ladyblog and head of the school blog. In one episode, after Alya gets suspended from school because of Chloé, she is infected with an akuma by Hawk Moth and becomes Lady Wifi, a cellphone and Wifi utilizing supervillain.

Appearance
Alya is at a medium height with dark skin and golden eyes. She has dark reddish-brown wavy hair that goes to her shoulders, the tips of her hair a lighter shade of red. Above her right eyebrow, she has a beauty mark.

She wears black-rimmed glasses with a light gray spot on each side, a white tank top underneath a plaid shirt with white, orange, and purple stripes, light blue jeans, and white sneakers with black tops.

Personality
Alya is shown to be a rather energetic and passionate girl. As Marinette's best friend, she is extremely loyal and supportive, going out of her way to encourage and (sometimes literally) push Marinette into spending time with Adrien, often offering to take care of her responsibilities for her. Alya is also very forgiving and accepting of Marinette's flaws, such as when Marinette accidentally deleted Alya's video of Ladybug (which resulted in the theft of Alya's phone for several hours), she immediately told Marinette that it was no big deal, though she was sad Marinette had not told her sooner, because she had already posted the video on her blog and had already expected something to happen when she showed Marinette the video, suggesting that she has good foresight and planning skills.

Alya has a dramatic side to her personality as well, such as when she pretended to be a unicorn with Manon and when she made an excuse to Adrien's photographer, who asked for her to be a support model for Adrien, so Marinette could do the modelling instead. She also tends to jump to conclusions, such as when she jumped to suspect Chloé of being Ladybug after seeing the mayor's daughter with a Ladybug prop yo-yo.

When it comes of anything involving Ladybug and Cat Noir, Alya easily becomes very excited and basically has a single goal of updating her blog as soon as possible, like when she was kidnapped by the Pharaoh Akuma to be a sacrifice. While being carried away, she filmed herself and livestreamed the video on her blog. In the same episode, she got annoyed when she was being replaced as a sacrifice, questioning the Akuma about her worth, hinting at a slightly more prideful side of her. She is intent on finding out who the civilian identities of the two superheroes are, and is willing to follow almost any lead she is given towards that goal.

Marinette Dupain-Cheng/Ladybug
Alya and Marinette are best friends, often hanging out with each other or helping each other out with something. While amused by Marinette's inability to act normally around Adrien, Alya encourages her to talk and do things with or for him, like giving him a birthday present or inviting him to a movie. Despite considering Marinette a ditz sometimes and perplexed by her constant disappearances, Alya loyally stands by her, and she appreciates Marinette's kindness.

Meanwhile, Alya is a huge fan of Ladybug, running a fan blog about her called Ladyblog. She is always trying to learn more about her, including her secret identity. In one episode, she reveals that she has figured out that Ladybug must destroy an important object of a supervillain in order to defeat them, impressing Ladybug. She also seems aware that she and Cat Noir's transformations are only temporary. Her search for Ladybug's identity is relentless, one time mistaking Chloé, a cosplayer, for being Ladybug. As Lady Wifi, her frustration with her search intensifies, complaining how heroes should not hide their identities.

Adrien Agreste/Cat Noir
Alya is congenial with Adrien. Not sharing Marinette's nervousness around him, Alya talks to him with ease.

Though not as interested in Cat Noir as Ladybug, Alya is a fan of him, finding him cute. She is also searching for his alter ego, at one point contemplating it being Adrien.

Nino
Alya and Nino get along nicely, sharing their confusion in how Marinette and Adrien are always disappearing. Overhearing Nino suggest to Adrien that they go to the movies, Alya asks him if she and Marinette can join them. Also, without Marinette to help her discover if Chloé is Ladybug, Alya drags him along and has him distract her while she takes a photo of Chloé's locker. In one episode, Alya works with Nino as a scriptwriter for Nino's homemade movie.

Chloé Bourgeois
Like Marinette, Alya detests Chloé. She finds her snobby and rude, but she recognizes that Marinette is more likely to suffer with Chloé than she is herself, feeling sorry for Marinette when she and Chloé are partnered up for a school project. During her searches for Ladybug's identity, Alya spots Chloé with a Ladybug-themed towel and a Ladybug yo-yo, these findings misleading her to think Chloé is Ladybug. After Chloé discovers that Alya took a picture of her locker and gets her temporarily suspended, Alya, enraged by Ladybug having such a horrible alter ego, goes to unmask her after transforming into Lady Wifi. She continues to believe she's found Ladybug's true identity until the real Ladybug and Cat Noir appear to save a cosplaying Chloé from Lady Wifi's clutches.

Manon
Alya bonds very easily with Manon because of her experience with younger siblings. She pretends to be a unicorn princess, exciting Manon, and during their entrapment within a shield of ice by Stormy Weather, Alya tries to entertain her in order to distract her from their dilemma.

The Pharaoh
While it's not known if Alya knows that the Pharaoh is Jalil, she figures out that his necklace his important item that Ladybug needs to destroy. Captured by the Pharaoh, Alya is both frustrated by her kidnapping and thrilled to be a part of the action while waiting for Ladybug and Cat Noir to show up. She takes time to ask him questions about his plan, and as soon as she figures out that she is his sacrifice, she is terrified, using her recording to call out to Ladybug for help. Amusingly, though, when Ladybug is tricking the Pharaoh to sacrifice her instead of Alya, Alya takes it as an offence, annoyed that the Pharaoh doesn't think she is a good enough sacrifice.

Sightings

 * Miraculous: Tales of Ladybug & Cat Noir Theme Song

Season 1

 * The Bubbler
 * Mr. Pigeon
 * Stormy Weather
 * Timebreaker

Trivia

 * Alya is the most recurring character of the series, appearing in every episode, alongside Marinette, Adrien,Tikki, and Plagg.
 * In "The Evillustrator", Lady Wifi reappears in Nathanaël's fantasy, teaming up with Stormy Weather to attack Marinette.