This chapter was so cute and funny!
I really wanna see more of the sisters, maybe teasing the main couple or something.
(Also, I know it's not yuri but... What if, huh?)
I like the foreshadowing here. From the last chapter and this, Riri didn't specifically mention she want to go to an athletic club, but the training and that time she admired the athletic club, lead you to assume so.
that's definitely what was required an airhead imouto-san, that family of theirs is really something and then the other "straight men" imouto RiRi. This series is heading in a right direction and is getting even more interesting with all these new characters we are seeing for the past few chapters.