Forbidden Individual Curse Tag

This is a cursed seal that is placed directly on the target's heart, and is designed to restrict them from performing certain actions such as taking their own lives or removing the cursed seal themselves. By directly striking their heart, the person branded with the juinjutsu can remove the seal, albeit risking their life in the process. According to Obito Uchiha, the cursed seal also interfered with him becoming the Ten-Tails' jinchūriki.

Trivia

 * Both Rin Nohara and Obito Uchiha, who were branded with this cursed seal, had it removed by Kakashi Hatake's Lightning Cutter separately, although Rin died while Obito survived – albeit barely – because he sealed the Ten-Tails into himself shortly after.
 * In the manga, the tag is black, with a Rinnegan-like symbol on it, while in the anime, it is white, with a red, white, and teal symbol.