Lanna (らな Rana), formerly known as Otonashi Rhythm (音無りずむ Otonashi Rizumu), is a female English / German / Japanese Virtual Youtuber.
Rhythm debuted on YouTube on 1 May 2018. Five months later, she revealed her 3D model on 29 September 2018. In March 2019, Rhythm erased her Twitter account and removed all videos from her YouTube channel. While no official statement had been made, it was clear that she retired. Since the second week of December 2019, the official website of upd8 no longer lists Rhythm as part of their roster of virtual talents.
On 19 September 2020, she would return to YouTube as a VTuber, reintroducing herself as "Lanna". Her channel now focuses on foreign language study/exchange, hence "V語学". She has since collaborated with other VTubers to stream in multiple languages for learning purposes.
On 15 November 2020, Lanna announced that she had joined VRIDOL, a new German Youtuber agency. She explained that she would be moving to a new channel and a new VTuber persona called Karen von Nachtingall, as her activities under the name "Lanna" were a temporary measure since she was unsure on what name to take. Despite the move, she said she would maintain the same type of stream content (languages and multiplayer game collabs) as Karen.