Nisekoi

Raku Ichijou is your Ordinary High School Student. Well, as ordinary as he can be, being heir of a Yakuza family, a position he's not too happy about. Still, he lives a mostly carefree life until one day he crashes into (or, more precisely, is crashed into by) Chitoge Kirisaki - his class's new transfer student. This causes him to lose his most precious possession- a pendant given to him by his first love ten years earlier. Some harsh words are thrown and even though Chitoge eventually helps him find the pendant, the two of them are off to a bad start.

If that wasn't enough, a new gang shows up in town and start getting into fights with Raku's family - a conflict that could escalate into full-blown gang war. Through the power of coincidence, the gang's leader turns out to be not only Raku's father's old friend, but also Chitoge's dad! Together the two heads devise a plan to calm down their rowdy subordinates: Raku and Chitoge will have to pretend to be a couple! The two of them are not too happy about that, but agree to play along to avoid a bloody conflict.

Thus starts a story of love, lies, twists and promises. How long will Raku and Chitoge manage to fake their feelings? And how long will those feelings stay fake?

Tropes in Nisekoi include:

Bromantic Foil: Shuu Maiko, Raku's best friend. Half the time he meddles to help Raku. Other half- because he thinks it's funny.
Bifauxnen: Tsugumi.
Censor Steam: Used repeatedly in Chapter 23.
Childhood Marriage Promise: One of most important plot points is that Raku made one with girl he knew ten years before the start of the series. Unfortunately he doesn't remember her name or face. His only lead is fact that she has key to lock in his pendant.
- It is revealed early on that Kosaki Onodera has a key from a childhood promise she made but seems unsure about.
- Later we find that Chitoge also made a promise with a boy whom she can't recall. In fact it's strongly implied that they made the promise with each other.
  - As of Chapter 27, Onodera claims to be the promised girl, when asked by Raku.
Class Is in Room X-01: Despite how generic many of this series' other elements are, it averts this. The class the main cast is in is 1-C.
Fan Service: Kept at very low level considering the genre... until the 2 part Hot Springs Chapter that is.
First-Name Basis: Chitoge decides that she and Raku should call each other by their first names after he saves her in the forest.
Genre Savvy: Shuu Maiko and Ruri Miyamoto
Lonely Rich Kid
Real Men Cook: Raku is an excellent cook- having to take care of his Yakuza family turned out to be a good training.
- The girls, on the other hand, are lethal chefs.
Memento MacGuffin: The pendant Raku carries is not only a memento of his first love but also the only clue he has of her identity.
- Onodera and Chitoge also carry around a key as a memento of a promise ten years ago. Sounds awfully familiar...
New Transfer Student: Chitoge transfer to Raku's class in chapter 1. She's transferred schools a lot before because of her dad's travels.
- Later Seishiro Tsugumi
Not So Different: At first Chitoge and Raku seem to be polar opposites, but eventually they find out that they have surpassingly similar experiences as heirs of crime syndicates.
Troperiffic: Think of a Romantic Comedy trope. There's good chance that it applies.
Unprovoked Pervert Payback: Averted. Raku walks in on Chitoge in the hot spring, but she quickly figures that it's because Claude switched the signs to destroy Raku's reputation.
- Played straight whenever Tsugumi is involved.
Wham Chapter:Chapter 13 in which Chitoge remembers that she once made a promise with a boy. A promise that is word for word identical with the one Raku made.
Yakuza
Zettai Ryouiki: Chitoge sports impressive Rank A one.