"Love Lessons" by Heidi Cullinan

This book takes place at a small, private college in Illinois where freshman Kelly Davidson gets an unexpected roommate, junior Walter Lucas.  Kelly is introverted and suffers from massive allergies, while Walter is a loud extrovert with a wicked reputation.  The only thing they have in common is that they're both out, but they bond over silly things and eventually come to depend on each other through tough times with families, classes, and bullies.  This was another cute story by this author, who lives in Iowa.  Walter was not very likable at first, but his relationship with Kelly calmed him down and made him a better person.  Kelly was adorable.  299 pages (Kindle edition).