Riho Sayashi

On March 27, 2011, it was announced Sayashi would be replacing Erina Mano for the radio show Mano Deli, renaming it Riho Deli. Sayashi was the only ninth generation member to receive solo lines in "Only You". On July 29, 2011 Sayashi was out of events for a few weeks to rest due to ischium nerve pain on her right side.

In July 2012, it was announced that Sayashi will be part of the new Hello! Project duo Peaberry, along with S/mileage's Ayaka Wada, and that they would perform their original song "Cabbage Hakusho" at the Hello! Project summer concerts. They were formed alongside the group DIY♡ to be part of Hello! SATOYAMA Life.

On October 29, 2015, it was announced that Sayashi will graduate from Morning Musume '15 on December 31, 2015 during the annual Hello! Project Countdown Live. On December 29, 2015, Morning Musume '15 released their 60th single; this was the last Morning Musume single to feature Sayashi.

On December 31, 2015, Sayashi graduated from Morning Musume and is now an artist under Hello! Project.

On December 7, 2018, it was that announced her contract with UP-FRONT PROMOTION had ended and she subsequently graduated from Hello! Project at the end of November 2018