Full Metal Panic! Short Stories Volume 2 by Shouji Gatou

Lifelong mercenary Sagara Sousuke’s struggles to fit in at a regular Japanese high school continue. He turns a turf war with delinquents into a hostage situation, investigates a local shrine for nuclear weapons, and sends a struggling rugby team through boot camp! He’s getting closer with his friend Chidori Kaname, too... but between almost losing an important assignment of hers—forcing them into a race against time to get home and back—and running recon on her first date with an old crush, he might be a little behind in the count! But however the game turns out, this is one batter that always swings for the fences!