It's Valentine's Day in Paris and Love is in the Air for Marinette when she finds a love note in the trash that Adrien had wrote and she assumes that Adrien has feelings for her, but he is actually in love with Ladybug. Marinette writes a love poem for Adrien in hopes of admitting her feelings for him. At the same time, Kim is determined to declare his love for Chloe by giving her a broach, but she humiliates Kim and she posts the picture on the Internet. Kim gets akumatized by Hawk Moth and he becomes Dark Cupid, he starts to seek revenge on Chloe for rejecting and humiliating him. Dark Cupid starts infecting the Parisians, including Alya, Sabrina, and Cat Noir with his hate arrows. Ladybug is able to break the spell on Cat Noir by kissing him and they defeat Dark Cupid. Unfortunately, Chloe's poster of Adrien gets vandalized by Sabrina and the two girls cry in anguish over the damage. In Marinette's room, Marinette doesn't remember that she signed the poem after talking with Alya and Adrien gets the love message that Marinette has wrote, but he thinks it's from Ladybug.
