Sasaki Stopped a Bullet(2013)

Sasaki-kun ga Judan Tometa

To Sasaki, his teacher Kawaguchi is God. She taught him not to be ashamed of his own dreams and made him feel fully capable to forge forward and make them come true, no matter how low the odds. Yet one day, trouble from Kawaguchi's past follows her into the classroom. With his god in danger of total humiliation, Sasaki sets out to protect his teacher using her very own teachings: to strive for the impossible.

(Source: MAL Rewrite)