Is Hayashimizu-senpai (seen in Fumoffu) Tessa’s older brother? All I remember hearing about the brother is that Tessa looked up to him and felt protected by him, that he was there when the family lived in Okinawa, and that he was able to do some crazy calculus at age 4. Reasons for this theory: well, white hair! And he’s very clever, and always reading. Also, when Tessa “transfers” to Jindai for a week in Fumoffu, she meets Hayashimizu, and his fan (which often sports amusing phrases) says “妹” (imouto), or “little sister”. Coincidence?!?!?!?
Side note: Full-Metal-Panic.com is a pretty cool website. (Hover over and refresh that splash page to find the secret areas. The “warning” text on them is funny :>)
Side side note: Sousuke is hot.