Born as Lösch Markus from Germany, Otsuka Ryunosuke moved to Japan in 2010 in search of classical martial arts. He met Otsuka Yoichiro of Hokushin Itto Ryu Hyoho, and quickly became a dedicated student and uchi-deshi. Just three years later, he was appointed Saiko Shihan (highest master) of the art. In July of 2014, Otsuka Ryunosuke earned Menkyo Kaiden (license of full transmission) from Yoichiro, who had since become the 6th Soke of the art. At that time is when he was taken on as an adopted son of Yoichiro and officially changed his name.
Now if you do the math, that is just over five years from virtually a beginner (he had some prior experience in Muso Shinden Ryu) to becoming the headmaster of a classical martial art. And the best part is that he's a very young guy and nobody questions him, nor should they! This is all too common in the world of traditional Japanese martial arts, but no one wants to talk about it because it contradicts everything their master told them in order to keep them paying tuition all those years. However, when the motivation for training is simply the art itself and you dedicate yourself to it, it is more than possible to reach high levels of proficiency and expertise in a relatively short time frame. It also reinforces the idea that certification is something special from teacher to student, and it's not for anyone outside of the art to question. We don't need to understand how or why such recognition was given, just acknowledge that it was and treat people with respect. After all, that's what martial arts are all about.
So from one inheritor to another... Otsuka soke, omedetogozaimasu!