Sometimes I just think about how in high-speed, there was that scene in their childhood where Haruka almost drowned and Makoto was so distraught over it he cried later.
Then I look at the Free! anime and how the staff decided to incorporate a similar scene. Except this time around older Makoto was the one who almost drowned while Haruka was the one frantic and panicking.
Like what better way to illustrate how important Haruka and Makoto are to each other, than show their reactions to the prospect of the other one dying? Because Tachibana Makoto and Nanase Haruka have that kind of relationship where they just can’t lose each other, they need each other.