What's this anime with a boy and girl meeting and becoming siblings?


The story is about a girl and a boy meeting after their parents went on a
vacation. When their parents came back they exchanged partners and the two
became siblings. Please help. I wont be able to sleep well until I remember
the anime. ;(




It's [Marmalade Boy](https://en.wikipedia.org/wiki/Marmalade_Boy). Originally
a manga, had an anime adaptation later.

From the Wikipedia page I linked above:

> Miki Koishikawa's ordinary life as a high school sophomore is turned upside
> down when her parents suddenly announce that they are getting divorced in
> order to swap partners with a couple they met in Hawaii. They seek her
> approval of the shocking change, and at a dinner where Miki meets the other
> couple as well as their son Yuu, who is about her age, she reluctantly
> agrees to the arrangement. Yuu, while at first a jerk who takes every
> opportunity to make fun of Miki, turns out to be fun and attractive, and
> Miki finds herself falling for him.

