Hanazakari no Kimitachi e, Tokyo Crazy Paradise Recommendations
Both have a girl disguised as a boy, and the boy they like knows they are a girl. Both are also hilarious!
This manga and TCP has some parts in common --- but not much--- if you wanted Hana Kimi with more Action and different time settings (somewhat) then this is the manga for you! its unique and very readable although there are some parts that were boring in between important events and all.... * note that this manga has everything to do with the Mafia ...
They both about a girl that hid the fact she's a girl, and how she has to handle with it, against her will.