Mia was getting ready to go to the studio when she arrive at the building and says, "Oh man! I forgot to talk to Cousin Marinette and open that present. No worries, I'll leave a reminder on my phone." Then, all of a sudden, Chanyeol accidentally bumps into her, causing them to drop their phones. Mia says, "I'm sorry Chanyeol."

"I should be sorry, I bumped into you," Chanyeol says. Their hands touched once they tried to grab for their phones. Mia blushes at this and says, "Um. Thanks for helping me." "No problem," Chanyeol says, "by the way, your mother's cream pastries were delicious!" "You ate some?" Mia asked in shyness.

Chanyeol explains, "Actually, a nice elder gave me one and said that you gave them to him after helping him." Mia says, "Well, I need to hurry. Me and the other Cupid members have a comeback to work on." She leaves after bowing to him while her face is red.

Chanyeol says, "That's odd. She's turning red." Baekhyun then says, "Hey Chanyeol. How was that song you're working on?" "Oh," says Chanyeol, "I didn't work on it. I was helping some elder home, and he treated me to tea and pastries." "Oh," Baekhyun says, "Guess what happened to me today!"

"Your fans sent you your favorite brand of eyeliners?" Chanyeol asks. Baekhyun says, "I wish. But no. I found a way to confess to the girl I met two weeks ago at Lotte World. I'm going to write her a song that expresses my feelings for her." "Are you sure it's the right time for that Baek?" Chanyeol asks, "You two only talked to each other for weeks."

"But I think I'm ready, I want to be able to tell Taeyeon that I love her," Baekhyun says. Chanyeol explains, "Just make sure she's okay with it. Women don't like to be rushed." Baekhyun nods as he runs off to the instrument room. Mia is in the middle of recording "I Spy" with the other members of Cupid. Just as they were wrapping things up, Mia's phone buzzes. "Mia," their manager says. She then says, "Sorry sir!" and completely silences her phone before they restart.

After the recording was done, Mia checks her notification to call Marinette. Hyunmi says, "You still didn't talk to your cousin?" "Ani," Mia says, "I was tired from the vigorous dancing, the singing, and helping that poor elder." "In a way it doesn't surprise me that you forget things sometimes," says Xin Mei.

Mia giggles lightly and says, "Yah. Typical me." "Make sure you talk to your cousin okay Mia," says Jimin. Mia says, "Okay." She runs out of the building to head home. Just then, Baekhyun was waiting in the room as Taeyeon arrives. She says, "What's the surprise you wanted to show me?" "I actually have to tell you something Taeyeon," Baekhyun says, giving her a necklace with a heart shape flashlight charm, "I want to play you a song as I tell you."

He prepares playing as he starts singing the lyrics he wrote in the song. Just then, after he is playing, Baekhyun gets on his knee and says, "Taeyeon, even though we knew each other for two weeks, I fell in love with you at first sight. I want you to be mine." Taeyeon didn't know what to do or say in that moment. She looks at the charm and gives it back to Baekhyun.

Then she says, "Sorry Baekhyun. But I don't think right now is a good time to be in a relationship with you." "Why? I worked hard on this to tell you how I feel," Baekhyun says. "I know you did, and I'm flattered, honestly," she says, "but we only knew each other for two weeks. I need to give it time before I accept your confession." With that, Taeyeon exits the building. Chanyeol was walking towards the exit when Baekhyun was running away.

Following him, Chanyeol asks, "Baekhyun?! Where are you going?" "Away?! I can't live in a world where a girl I love won't accept my feelings!" Baekhyun says, tears streaming down his face as he ran away. Chanyeol was gonna chase after him, but knew it was getting late, so he went home, saying, "I'll talk to him on the phone."

Just then, Hawkmoth observes Baekhyun and says, "Ah. Just what I need, a heartbroken soul who isn't willing to give up the love of his life. His sadness is the perfect fuel for my akuma." He then evilizes a butterfly and says, "Fly away my akuma, and evilize this frustrated celebrity."

Baekhyun was sitting in his home, locking himself in his bathroom, crying over Taeyeon. Just then, the akuma touches the necklace Baekhyun was clutching to. A pink outline of a butterfly appears around Baekhyun's eyes.

Hawkmoth says, "Hello there Luminator. My name is Hawkmoth. I am giving you the power to use your light to help take out your sadness and anger on anyone who tries to stop you from getting your dear lady. But you have to give me the Miraculouses of Ladybug and Black Cat in return." "Taeyeon will love me, and I'll make sure no one says otherwise!" Baekhyun says, evilizing into Luminator.

Mia was in the middle of FaceTiming Marinette while holding into her box. Marinette says, "Before you tell me about your new album, I need to tell you something Mia." "Yes Marinette?" Mia asks. Marinette says, "You got a box right?" "Yes," says Mia, "Why?" "Open it, and then I will explain," Marinette tells her cousin.

Before opening, a news story appears, with Park Yoora reporting it, saying, "Breaking news in Seoul. Just earlier, a mysterious villain by the name of Luminator has been terrorizing everyone using his light powers, and imprisoning anyone who tries to get in his way. The Seoul Police Department is doing everything they can to handle the situation." Mia looks at Luminator and thinks to herself, Baekhyun?

As she opens the box, she sees a pair of ladybug earrings. After taking them out, Mia screams when a kwami appears out of nowhere. Marinette says, "Hey Tiki. Long time no see!" "Hello Marinette!" Tiki says. Mia scream, while swinging a fly swatter, and says, "Bug! BUG!!" She traps Tiki in a glass and says, "Cousin Marinette. What is this?"

"Listen Mia," Marinette says, "There's a secret me and Tiki need to tell you. It's a secret that you have to keep to protect Seoul." At Chanyeol's place, he saw the news, and recognizes the necklace. "That looks like Baekhyun's necklace," he says while opening his box. Just then, he see a black cat ring, and a little kwami flies out.

Chanyeol screams and asks, "What are you?!" while swatting him away. "My name is Plagg, an I'm a kwami," says Plagg, "I am here to grant you the power of destruction so you can protect Seoul. You are to become the new Black Cat" "Me. Black Cat? What's going on?" Chanyeol asks.

Plagg says, "I know you're the famous Chanyeol of EXO. And I also know your friend Baekhyun was akumatized into Luminator. A new Hawkmoth is trying to do what the old Hawkmoth did in Paris. Try to gain ultimate power with the Miraculouses of the ladybug and black cat. You Chanyeol, are the chosen one."

"Chosen one?" Chanyeol ask. Mia asks, "Chosen one?" "Yes Mia," says Tiki, "You have to take Marinette's place to protect Seoul. You are to become the new Ladybug and save Seoul." Putting on the earring, Mia asks, "So I have to use my luck charm to stop Luminator, and break the object of the akuma?" "Yes," Tiki says.

Marinette says, "And when you do, you need to capture the akuma and purify it. If you don't, the akuma could spread. I made that mistake when I first became Ladybug, Mia. So don't do what I did." "Okay Cousin Marinette," Mia says, hanging up, "so Tiki, how do I transform." "Leave that to me, you just say 'Spots On!'" Tiki says.

"Okay Tiki. SPOTS ON!" Mia says. Tiki gets into the earrings as Mia transforms into Ladybug. Chanyeol puts the ring on and says, "The cataclysm is only used once, and I swipe or touch the object to destroy." "Pretty much," Plagg says, laying on Chanyeol's piano, "to transform, say 'Claws Out.'" "Okay," Chanyeol says, "Claws Out!" Then he transforms into Black Cat. Chanyeol looks at himself and says, "Now time to go find Ladybug."

Mia looks at herself in her mirror and asks, "Tiki. Where are you?! If you can hear me, I need some tips!" She then sees Luminator entrap two police officers and says, "I'll save you Baekhyun!" Grabbing the yo-yo, Mia says, "Really. A yo-yo? What and I suppose to do with---. AAHHHHH!" as she flings the yo-yo towards a far away building.

Just then, Chanyeol hears a scream, and Mia lands towards him, saying, "Sorry. I was trying to figure out how to use my weapon. My kwami didn't quite explain everything to me." "It's okay," Chanyeol says, "I'm Black Cat. And from what my kwami says, you must be my partner Ladybug. Might I say, you do look gorgeous."

"You're quite the flirt aren't you kitty?" Mia asks. She then sees Taeyeon and says, "But you need to find a better time to use your silly charms on me. I heard that that's a girl who is going to be victim to the akumatized villain." "So what's the plan," Chanyeol asked, grabbing his staff. Mia says, "We need to find the akuma's hiding spot, break the object it hides in, and capture it before it spreads." "Okay!" Chanyeol says.

Hyunmi was running towards the bridge, with her phone, taking pictures of the action. She says, "Oh my gosh! They're the legendary superhero duo! Ladybug and Black Cat! Now they're here in Seoul." As they were jumping on top of buildings to find Luminator, Mia says, "Where is Luminator at?"

"Other than searching for Luminator, are you happen to also be searching for a new boyfriend?" Chanyeol asks flirtatiously. Mia groans and says, "Black Cat. Can't you see we're a little busy at the moment?" "I apologize My Lady," Chanyeol says, bowing, then winking at her. Mia simply rolls her eyes at him, then she spots Luminator, saying, "Time for lights out, Luminator!" She flings her yo-yo towards a lamppost as Chanyeol leap in the same direction as the yo-yo.

Luminator growls as he sees Taeyeon and entraps her in his levitating light dome. She yells, "Who are you?!" "Taeyeon! Why don't you love me?! I did everything I could to impress you!" Luminator says, using the light necklace to weaken her. Taeyeon groans in pain and asks, "Baekhyun?" "Not anymore! I'm Luminator!" Luminator says.

Taeyeon says, "Let me go Baekhyun!" "You heard her Luminator!" Mia says. Luminator sees them and growls, "Ladybug! Black Cat!" Hawkmoth explains, "Those two have the Miraculouses I need for ultimate power. Bring them to me Luminator!" "I will not allow you to separate me and Taeyeon!" Luminator says, "I'll not imprison you in my light domes if you hand over your Miraculouses!"

"Never Luminator!" Chanyeol exclaims, using his staff to combat Luminator. Luminator then makes two powerful balls of light energy, and throw them towards Chanyeol and Mia. Mia uses her yo-yo to shield her and Chanyeol as she observes the necklace. "Black Cat, I believe the akuma must be in that light charm on Luminator's necklace," says Mia.

Chanyeol says, "Okay!" They chase Luminator as he climbs onto the top of the torch statue of the Olympic Bridge. Taeyeon says, "Why are you doing this Baekhyun?!" "So you and I can be together forever Taeyeon!" Luminator says, "I love you more than anyone else out there!" Just then, the rest of the cops come by and try to stop him, but Luminator yells, "BLINDING RAYS!" and has a beam of light blind the policemen as they gathered on the bridge. Just then, Mia and Chanyeol arrived when they get ready to stop Luminator. Taeyeon says, "I'm terrified of heights! Help me!" "Don't worry," says Mia, "we'll get you down!"

Mia yells, "Lucky Charm!" as she tosses her yo-yo into the air, then a full-length ladybug printed mirror appears and she asks, "What am I suppose to do with a mirror?" She uses her lucky vision to see, and the necklace glows, as well as the torch of the bridge, Luminator and Taeyeon's ankles, and the mirror. "Black Cat, use your power on that torch after I prevent Luminator from attacking!" Mia says.

Chanyeol says, "Okay Bugaboo!" Luminator uses his blinding rays again, but Mia uses the mirror to reflect those rays in his face. Chanyeol yells, "Cataclysm!" and touches the torch, causing it to disintegrate and make Luminator and Taeyeon fall.

After freeing Taeyeon from the dome, Mia uses her yo-yo to grab her and Luminator by the leg, and she snatches the necklace, stepping on the light charm. She says, "Your evil doing days are over little akuma." Mia uses the yo-yo and says, "De-evilization time!" trapping the akuma. She releases it and yells, "Miraculous Ladybug!" throwing the mirror into the air. Then everything turns back to normal, and Baekhyun gets out of his transformation as Luminator.

Hyunmi runs up to Mia and asks, "Are you going to protect Seoul from now on Ladybug?" "Yes, along with my new partner Black Cat!" Mia says. Chanyeol says, "See you around LB," then flashes her a smile as he winks at her. Mia says, "Yeah. See ya," in a slightly annoyed tone.

She and Chanyeol leave when their charms are telling them they're about to switch back. Just then, Taeyeon walks up to Baekhyun, grabbing the necklace, saying, "Baekhyun. I'm sorry about before. I didn't know you were so hurt. How about we go on a date tomorrow?"

Blushing, Baekhyun says, "Of course." "Okay," Taeyeon says, "See you at Lotte World." She leaves after kissing his cheek, causing Baekhyun to say, "She does like me?" Hawkmoth says, "No! I was close to achieving the Miraculous! This is only the first round Ladybug and Black Cat! Your Miraculouses will be mine!"

Mia says, "Spots Off!" and gets out of transformation. Tiki says, "Great job Mia. I think you and Black Cat did great." "Maybe being Mia Kim of Cupid and being Ladybug won't be so bad," Mia says.

At his place, Chanyeol says, "That was fun Plagg!" "Just remember, you can't tell anybody this secret, not even close friends," Plagg says, eating his Camembert cheese. Chanyeol asks while holding his nose, "But do you have to eat that stinky cheese?!" Plagg asks, "What, it helps boost my energy so you can transform."

"Won't be easy to hide this secret if I stink of Camembert all day," says Chanyeol, laying down in bed. "Don't sweat it," Plagg says, flying towards Chanyeol, "once you get the hang of it, you'll get use to being Black Cat." "I guess you're right little buddy," Chanyeol says, turning out the light so he can go to sleep.

The next week, Mia was live on Mnet, premiering "I Spy" with Cupid. After they were done, the crowd cheers. Once Mia changed, she heads towards the door, but it started to rain and she forgot her umbrella. "Oh no! It's raining!" Mia says, sighing. Just then, Chanyeol sees her and says, "Did you forget your umbrella again Mia?" Mia turns to him with a red face and said, "Um. I-uh! Y-yeah."

"Let me walk you home," Chanyeol says, with a smile. They walked to Mia's house under his umbrella. At the doorstep, Mia asked, "How has Baekhyun been since Ladybug and Black Cat saved him from Hawkmoth?" "He's been fine," Chanyeol says, "and actually, him and Taeyeon have been talking more, and it turns out, they have a lot in common. They've been dating since the incident."

He pulls up pictures on his phone that Baekhyun sent him, and showed Mia. She says, "Aw. They look so cute together. Anyway, Thanks for Bringing me home Chanyeol."

"Anything for you Mia. See you tomorrow," he says, winking at her as he left for his place. Mia's jaw dropped as she dropped her purse on the porch, stuttering, "See you to-tomo-tomorrow! Ugh! Why am I stuttering so much. He's my friend!" "I think I know!" Tiki says with a small giggle.

Plagg pops out and says, "That was kind of you. First week of being a superhero, and you already have yourself a lovebug." "Don't be ridiculous, Plagg," Chanyeol says, blushing slightly with Mia and Ladybug on his mind, "Mia is just a friend. And Ladybug is my partner in crime." "Say what you want Lover Boy," Plagg says. Ho-ming says to Wayzz as he observes Mia and Chanyeol, "I think those two are meant for each other Wayzz." "Indeed they are Master Ho-ming."