Menma creates a Rasengan from negative chakra and surrounds it with an additional disc-shaped ring of chakra that orbits the main sphere, causing it to resemble a small planetary ring.

Trivia

• The technique's name is a pun, similar to certain techniques of Kumogakure ninja, in which it has an English name with a given kanji that somewhat match the pronunciation. In this case, "輪虞" is pronounced as the English word "ring", but literally means "fear wheel".
• The proper spelling of the technique's name was first revealed in Naruto: Shinobi Masters, a Japanese social game available for iOS and Android phones on the GREE mobile social gaming platform.