I apologize for being off the current topic.
Riku and Shoya have actually been training together for at least 2 years now. However, this past season was their first competing internationally. With Ami Koga's unfortunate injury and dissolved partnership with Spencer Akira Howe, Riku and Shoya were sent to Mentor Torun Cup to gain the minimum TES needed to qualify for WJC.
They've recently started working on a 3LzTh. It still needs work, but on April 15, both Riku and Shoya uploaded a clip to their twitter accounts (@BestShoya @miurariku1217) of them practicing this throw jump. I would've posted a link but can't since it's my first post here.
Also, for anyone interested and able to read Japanese, back on September 25, 2015, Shoya retweeted a link to an interview he did with J Sports where he talks about his experience as a beginner Pairs skater. Sorry, but I am not proficient enough to translate.
Rikako and Aru have been skating together since 2014. You've probably seen them compete before since they've participated in JGPs and WJC for the past two seasons.
With Rikako and Aru moving to Seniors next season, there seems to be a lot of anticipation for promising Ice Dance team of Utana Yoshida and Takumi Sugiyama to make their Junior debut.