While the young Angelique lives out her days peacefully in her school, attacks from the monstrous Thanatos has been increasing everywhere else. Two Purifiers show up one day, men with the power to exterminate the Thanatos. One of them, Nyx, attempts to convince Angelique to join them in their work, as she has the power to be the only female Purifier. As Angelique hesitates, a Thanatos shows up in their school. Nyx and the other Purifier, Rayne, fight a losing battle. With her classmates falling prey to the Thanatos, and the Purifiers beaten to submission, Angelique's desire to save everyone awakens. She became the only female Purifier in their land of Arcadia, the one known as the "Queen's Egg".

High school students Yuma Okazaki and Hotaru Mizushina are childhood friends. With their respective boyfriends, Takeda and Fujiwara, their lives couldn't be more perfect. From playing in school to going on group dates, it seems nothing can break their bond. However, during one such group date, Hotaru makes an unexpected move. While Takeda and Fujiwara are distracted, she begins stroking Yuma's thighs. Taken aback by this peculiar action, Yuma awkwardly retreats to the toilets, followed shortly by her aggressor. Now in private, Hotaru forces the innocent Yuma into a locked cubicle and whispers into her ear: "You'll be more nervous with a boy; I'll help you practice." [Written by MAL Rewrite]

Raku Ichijou, a first-year student at Bonyari High School, is the sole heir to an intimidating yakuza family. Ten years ago, Raku made a promise to his childhood friend. Now, all he has to go on is a pendant with a lock, which can only be unlocked with the key which the girl took with her when they parted. Now, years later, Raku has grown into a typical teenager, and all he wants is to remain as uninvolved in his yakuza background as possible while spending his school days alongside his middle school crush Kosaki Onodera. However, when the American Bee Hive Gang invades his family's turf, Raku's idyllic romantic dreams are sent for a toss as he is dragged into a frustrating conflict: Raku is to pretend that he is in a romantic relationship with Chitoge Kirisaki, the beautiful daughter of the Bee Hive's chief, so as to reduce the friction between the two groups. Unfortunately, reality could not be farther from this whopping lie—Raku and Chitoge fall in hate at first sight, as the girl is convinced he is a pathetic pushover, and in Raku's eyes, Chitoge is about as attractive as a savage gorilla. Nisekoi follows the daily antics of this mismatched couple who have been forced to get along for the sake of maintaining the city's peace. With many more girls popping up his life, all involved with Raku's past somehow, his search for the girl who holds his heart and his promise leads him in more unexpected directions than he expects. [Written by MAL Rewrite]

Despite having seemingly quelled the war between their respective gangs, Raku Ichijou and Chitoge Kirisaki still carry on with their fake relationship. Eventually, as Chitoge's perception of Raku slowly changes, she even begins to see him as a little charming. Chitoge struggles to come to terms with her newfound feelings for Raku, as a new girl joins the slew of Raku's admirers and the competition among those vying for the yakuza heir's attention grows even fiercer. And amidst all this, Raku's search for his first love and the contents of the mysterious sealed locket continues in Nisekoi:, which picks up where the first season left off. [Written by MAL Rewrite]