It has been announced that Riho will be releasing her compilation photo book on 25th December 2015.
This photo book consist of her time active in Morning Musume. From the year (2011) she debuted till 2015.
If you were to pre-order it from Wani Books which already comes with a L Sized Photo, there are three types of bonuses you might get.
First: Original Photo (Only 1)
Second: Original 2L Sized Photo (2o people will win it by lottery)
Third: Having the photo book signed by Riho with your name in it (50 people will win it by lottery)
Other sites will have their different variations of the bonus L-Sized Photos.
The price of the photo book is ￥2,500.
Cr: Wani Books