Love the idea of a countdown put in the manga... helps the reader see the story moving and resolving in a timely manner.
I’d like to see the differences of intellect between the two MC’s. One demonstrates a higher IQ, as in being very perceptive of surroundings; while the other shows a higher EQ, or better perception of others around her. The bottom ranking student might not be the brightest bulb when it comes to facts, but she has a mature, realistic perspective on the real world.