Queen of the Otaku: There can be Only One

My name is Hajime Namikawa. I'm just your everyday university student, and I belong to the Manga Club, which—you guessed it—is really just the nerd club. There's one beautiful rose among our motley crew: Ai Himeki, who always has a smile and a kind word for any of us. She keeps the atmosphere warm and friendly, making the club the nice place that it is. This year, though, we've got a new first-year member: Mahiro Hanasaki. She joined our club for some reason, even though she's cool and popular-looking. Everybody is starting to love her already, since she seems so interested and doesn't look down on us. Can you guess what the problem is?