Due to Riho’s graduation having happened by the time the outfits were being decided (combined with the fact she’d already departed by the time the series began and said departure was announced days before the project was), her outfit became the dress she wore for her ceremony. Riho was also not featured during the entire voting process, due to her graduate status.
For references, I could’ve looked to an old photo I used to promote the event. However, I decided to go the extra mile and looked for Hello! Station footage of her graduation ceremony. As I primarily did this on the phone, this has left some of the details lost and I apologize for that. (This is the same deal with Kanon’s pic, only exacerbated for reasons explained in her section.)
I repeated the same segment over and over and over again — and it’s probably good that I listened to most of it, especially the part where they performed ENDLESS SKY because watching Weeping Musume 15 would probably get me choked up. Doing these first two images is going to set people (myself included) off to begin with!