Kimiiro no Koi

When Yosai was in the second grade, she was in a car accident, but thanks to a mysterious "hero", her life was saved.
One day, Yosai was about to get trapped in an elevator when an older boy suddenly appeared to tell her that she is in danger.
That boy is the same person who saved Yosai from the accident!
He has the mysterious power to "see danger in color" like a signal...?

(Source: Shueisha, translated)

Note: Includes 1 extra chapter.