Touhou wikia said:
... Nue and Murasa being the children of the team, so they often fight over who likes Byakuren better.

I support this now.

Awww, poor Kogasa wants in too.

I just adore how Nue and Murasa are both trying to get Byakuren's arms (along with the nice eye colouring done by the artist on both of them), just how disgustingly adorable Nazrin looks like a small child and with those ears, and Kogasa in the background there. Hang in there, Kogasa-chan ;_;