Chinkamo Twins! (Update Android ver)

The twin sisters, who love their brother, were approaching the crisis of year-round.
My brother is a teacher at the school where my sisters go, but I want to do something about it. However, the
two who hated studying were not motivated at all and had no sense of crisis.
A study group of three people will be held under the condition that if you study, it is better than usual.

Two people who gradually become bolder and become aware of their feelings.
The two people who wanted to occupy their brothers became baked and competed with each other.
What will happen to them?