A Goddess Comes to Japan (Part 1: The Suffering)
During a lull at the Mithril base, Tessa decides to spend the time as an exchange student at Sousuke's school to learn more about school life. Sousuke, however, finds the stress of guarding her overbearing and collapses from fatigue.
Aired 21/10/2003EP 7 - A Goddess Comes to Japan (Part 1: The Suffering)

Full Metal Panic? Fumoffu
It's back-to-school mayhem with Kaname Chidori and her war-freak classmate Sousuke Sagara as they encounter more misadventures in and out of Jindai High School. But when Kaname gets into some serious trouble, Sousuke takes the guise of Bonta-kun - the gun-wielding, butt-kicking mascot. And while he struggles to continue living as a normal teenager, Sousuke also has to deal with protecting his superior officer Teletha Testarossa, who has decided to take a vacation from Mithril and spend a couple of weeks as his and Kaname's classmate.
(Source: Anime News Network)