Nisekare (Kari)

Nanami Uchida has been dumped by her boyfriend and decides to go to a work party, where she drinks a lot. Her colleague Sakuma invites her to continue the evening in another bar alone with him. He takes the opportunity to ask her to be his girlfriend. Under the influence of alcohol, Nanami accepts. The reason Sakuma wants a girlfriend is... that women give him too much of a head start and he thinks it's boring! How will this fake couple evolve?

(Source: MangaUpdates)

Included one-shots:
Volume 1: Junjou Bitch
Volume 2: Tokujou no Ai wo Hitotsu
Volume 3: Honne wa Yoru ni Natte kara