@zdarkbrz_816 I actually have no problem if it completely change to casual cuddling. Though, It doesn't need to while still can keep the weekly teasing chapter and the relationship remain be the same, It can show how different they act after time to time to show the two getting closer bit by bit.
Make some change make it more interesting or else it can easy become repetitive. There are good example they done it very well.
Like that manga with the girl good at study but love sleep during class.
Or that 'the girl i like forget her glass'
And Watashitachi wa Koi wo Shiranai