The single's first song and main A-side is "Tsumetai Kaze to Kataomoi", whose official translation is "The Cold Wind and Lonely Love". The song was originally intended to be Riho's graduation solo song, however, the song was rearranged to include all members so that it can be promoted into 2016, after Riho's graduation. The song is a melancholy ballad that has sprinkled EDM dance breaks which sounds bad in written form but actually works very nicely in the song itself. The dance breaks are specifically for Riho to perform her solo dance(s) as she is known for being an AMAZING dancer.
I'll be honest, I'm kind of upset Riho herself didn't choreograph these solo's since I think she would do a much better job, but eh, she pulls it off. Some of the dance steps seem a bit off in certain parts but overall, she does a great job and this song stands as a great homage to Riho's skill and status as ace of the group during her tenure. The music video does a good job of showing us how much Riho has grown and her solo dance breaks are especially good because they really reflect Riho as a person: a solitary girl with great talent and a passion for performing. This music video is definitely my favorite of the three.
Endless Sky is the second song on this single and while Tsumetai was meant to be Riho's solo graduation song, Endless Sky is her actual graduation song (at least in my eyes). The song speaks about growing up, experiencing love, and not regretting the choices made to go on your own path and live in the way you want to live. Riho made a surprising choice for many when she decided to graduate, but she is certainly going down her own path in a determined manner. Her solo line(s): "I'm not going to cry, I'm shouldn't be crying; I chose this future" reflect her situation perfectly and are very nicely placed in the song. I love the cascading piano notes and the music video, while pretty basic, is still pretty to look at, haha. I would have liked a more heartfelt music video, with scenes from past concerts maybe even audition footage, but oh well :/ Btw, that solo line's meaning really hits home in this live performance. Clearly, it was hard for Riho to keep her feelings bottled up at the end of her final concert tour with MM (and it was also hard on the other members as you can clearly see them crying as well).
The final song on this single is the one that symbolizes a move toward the future. Here, 12th generation member Miki Nonaka takes center stage as the main vocal. One and Only is sung entirely in English - the first time Morning Musume has done this in it's 18 year history. All of the members take part and you can hear that they all worked hard on their pronunciation. The song has pop rock undertones and a (imo) great dance break. I for one, was quite happy that the dance break has Ayumi, Riho, and Macchan in the center because I feel like Maachan will be filling in Riho's shoes as center, so it was good to see some spotlight on her as well :) The song is your typical idol pop, nothing too special apart from the fact that it's all in English - oh, and the music video is really fun. I especially like how the lyrics show up in the background in that funky font.
Overall, I quite like MM's final single for 2015. I think it was well balanced and really touched on the many aspects that fans have wanted for a while. It's a solid good-bye single for Riho and I rate it overall at a 4.5/5. We (Riho fans) also got an awesome homage video, which I really like and was pretty much the kind of video I wanted for Endless Sky. One last picture of Riho, for old time's sake ;) I still plan on following her career of course, it will just be a lot harder since she won't be in an idol group. Still, best of luck to her in her next stage in life and I look forward to MM '16!