"Nisekoi" is a romantic comedy anime series centered around Raku Ichijou, the heir to a yakuza family, and Chitoge Kirisaki, the daughter of a rival gang leader. To prevent a gang war, Raku and Chitoge are forced into a fake romantic relationship, pretending to be a couple despite their mutual dislike for each other. This arrangement complicates Raku's life, as he has been carrying a locket since childhood, a memento from a promise he made to a girl he once loved. The locket is a key to his past, but it can only be opened with a matching key held by the girl he promised to marry.

As the story progresses, Raku's life becomes entangled with several other girls, each of whom could potentially be the one he made the promise to. Onodera Kosaki, Raku's shy and kind classmate, harbors feelings for him but struggles to express them. Marika Tachibana, a persistent and determined girl, openly pursues Raku, driven by her own childhood connection to him. Tsugumi Seishirou, Chitoge's bodyguard and childhood friend, also becomes involved, adding further complexity to the relationships. The series explores the dynamics between these characters as they navigate their feelings, rivalries, and the challenges of maintaining the fake relationship.

The narrative is driven by a mix of comedic misunderstandings, heartfelt moments, and romantic tension. Raku's search for the girl with the matching key serves as a central plot device, creating a sense of mystery and anticipation. The series balances lighthearted humor with emotional depth, as the characters confront their insecurities and pasts. While the fake relationship between Raku and Chitoge begins as a farce, their interactions gradually reveal a deeper connection, complicating their feelings and the relationships with those around them.

"Nisekoi" is structured around episodic arcs that focus on the interactions between the main characters, often highlighting their individual struggles and growth. The series maintains a steady pace, blending comedic scenarios with moments of introspection and romance. The interplay between the characters' personalities and the evolving dynamics of their relationships form the core of the narrative, creating a engaging and multifaceted story.