That was one hell of a chapter. Rin's reaction to Nemu being legitimately interested in the movie was great and I'll never get tired of Karane and Hakari's interactions.
I think that it won't be bad, if also others besides Karane and Hakari started kissing. And why limit yourself to just couples, let love flow through the whole family.
The reason these 2 do it is because they shared their first kiss with Rentaro, so their love for him is also kinda connected to each other.
There is also a theory that, since they were all kind of looking at each other when the first thing happened, that this might be an actual three-way soulmate situation but these two don't want to admit it.
At this point it’s missing the Girl’s Love tag. The yuri vibes are strong between the girls.. it’s officially the 100 girlfriends that really really really love each other… and Rentarou.