The main female protagonist of the question arcs, Rena is a kind girl who is also naïve and usually the subject of teasing by Maebara Keiichi. She loves all things she considers adorable calling them "kaii" which is actually "kawaii" only slurred. She also likes to take them home, and is virtually unstoppable when doing so. She also tends to utter the phrase "hau" when she is excited or flustered, and has a habit of repeating phrases at the ends of her sentences.
Beautiful Rena by Kipi! I wasn't sure which anime this was from, but Tama-chan was a big help with that! Thanks again for the contribution, Tama-chan!