Kuragehime is similar, and it's possible I love it more than Kimi No Todoke (which I love a lot!)
The story revolves around Tsukimi. She's a jellyfish otaku and lives in a boarding house with four other room mates, all extreme otaku of their own types. They call themselves 'Amamizukan" which, if I remember right, basically translates into "Convent" for nuns. No men are allowed, and all five women are extremely shy around normal people and especially shy/afraid of men.
Enter Kuranosuke. He's the illegitimate child of a high ranking politician and also a cross-dresser. He helps out Tsukimi with obtaining a jellyfish from a pet store, and she, finding him extremely powerful and beautiful, invites him back to her place not knowing he's a man. Well, she finds out and flips.
Turns out Kuranosuke takes a great liking to her and her flatmates and wants to change their ways. It basically goes from their with a seriously adorable love story, very, very like Sawako's and Shota's. The biggest difference is it's not set in high school.
My summary is really weird, but it's a great series, and I think you should try it out. Here's where I watch it on anilinkz:
http://www.anilinkz.com/category/kuragehime/My biggest problem with the series is that there's not nearly enough episodes! Come on, Season 2!