I can't be the only one who absolutely adores the relationship between Raiha and Fuutarou, right? A healthy sister-brother relationship that's wholesome to boot? Never gets old. We can see throughout the manga (I haven't watched the anime) that Fuutarou is extremely motivated by his desire to give Raiha a proper life (though his motivation later expands into his friendship with the quintuplets).
---SPOILER WARNING--- (Why are you on a wiki discussion thread if you haven't finished the manga you fool?)
At the wedding timeskip, even as Fuutarou goes to marry Yotsuba, Raiha still helps him with the rings and remember them. He relies on her even when he's 22.
Additionally, Raiha gets along well with Itsuki Nakano, something that allows the two [, Itsuki and Fuutarou] to become closer through a mutual individual [, Raiha].
If ya'll see this, I wanna hear your opinions and thoughts on Fuutarou/Raiha the relationship (i.e. do you enjoy the dynamic? etc.).