Some may think this chapter is important because of the cuteness and the so relevante step of a videocall, others may say it is because of the bo*** and natural way of giving fan service... but no... don't lie to yourselves, you know da** well why this chapter is so important...
This is the chapter...where ONEE-CHAN gets completely introduced and involved in the plot. This is the chapter where the author gives us a first true look into what will come with the best supporting character ever! :)