Weiß Kreuz (Japanese: ヴァイスクロイツ, Hepburn: Vaisu Kuroitsu, literally German for "White Cross", written "Weißes Kreuz" or "Weißkreuz" in German) is a series conceptualized by voice actor Takehito Koyasu about four assassins that work in a flower shop called "Kitty in the House".

The assassins are members of a group called Weiß (white), which is run by Persia of the mysterious Kritiker organization.

The four voice actors of the main characters – Koyasu, Hiro Yūki, Shin-ichiro Miki, Tomokazu Seki – formed a band named "Weiß"; several CDs and singles were released.

Four young men consisting of Omi Tsukiyono, Ken Hidaka, Youji Kudou, and Aya Fujimiya, are members of a group of assassins called "Weiß".

An assassin group that is under the order of Kritiker ("critic" in German), a secret organization that falls under the Japanese police force.

The main enemies in the series are another group of assassins called Schwarz ("Black" in German), all of whom have supernatural powers.

Later in the series, Schwarz is seen assisting a mysterious group known as "Eszett" (the name of the German alphabetic character ß) in resurrecting their deceased leader.

Weiß - An Assassin and White Shaman, illustrated by Kyoko Tsuchiya and story by voice actor Takehito Koyasu, was serialized in the shōjo manga magazine Wings, published by Shinshokan.

It is published by Ichijinsha; the first twenty-one chapters were serialized in the monthly josei manga magazine Comic Zero Sum and chapters twenty-two through thirty-seven were serialized in the quarterly shōjo manga magazine Comic Zero Sum Zōkan Ward.

Weiß Side B ended with the publication of chapter thirty-seven in the Summer 2007 issue of Comic Zero Sum Zōkan Ward.

The beginning episodes lend some back story to Aya, Ken, and Yoji, and show their motivations for being in Weiß.

The second Weiß Kreuz series, Verbrechen & Strafe ("Crime & Punishment" in German), is a two-episode OVA that takes place a short time after the end of the anime, and before the events detailed in the last set of Drama CDs.

In hiding, Aya, Ken, Yoji and Omi work out of a mobile home, using their flower-selling business as a cover.

Several of the original Weiß members are not immediately visible; two new ones are introduced in the first episode: namely Sena Izumi and Kyou Aguri.