Manga by author Komi Naoshi

On May 9th, 1999, Raku Ichijou was born into the Yakuza heir. On June 7th, 1999, Chitoge Kirisaki was born into the Bee Hive Gangsters. Even though Raku may be the next heir to a Yakuza group, he's actually a normal highschool student who wishes for peace and quiet. However, when he meets violent transfer student Chitoge Kirisaki, his life takes a sharp turn for the worse!

What do you spend the time left of your life when it's measured in heartbeats? This is the story of Hato Iijima and Hatsu Takagi, connected to each other by a rare disease called "Tempocardy".