Naezono

Canon
Makoto and Sayaka never officially dated, even prior tragedy, but they did go to the same middle school. When they were in middle school they never conversed but it is revealed that Naegi had a crush on Maizono, and Maizono was touched when Naegi rescued a crane from there school pond.

Speculation and Assumptions
Even though Maizono attempted to frame him for murder, she wasn't sure about it, and hesitated. This caused her to die. Even after it was revealed that Maizono attempted to betray Naegi, he forgave her.