I got everything too! The Evening Cherry Blossom High Heels took forever to get, I kept getting more of the Cherry Blossom High Heels and the Cherry Blossom One Piece over and over.
Here's a list on what songs (for me) gave which items:
Brainstorming: SR Uemura, Sakura High Heel
The Peace: SR Uemura, Sakura Ornament
Ren'ai Revolution 21: SR Uemura, Sakura Ornament (2x), Sakura One Piece, Sakura High Heel (2x)
One Two Three: SR Uemura (2x)
Kimagure Princess: Sakura Ornament
Want! : Evening Sakura High Heel (2x)
Special Generation: Evening Sakura High Heel
Crazy Kanzen na Otona: Sakura High Heel (2x)
Dance de Bakoon: SR Uemura
Uchouten Love: Nothing =(
Yume Miru 15: SR Uemura (3x), Evening Sakura High Heel (6x)
Tabidachi no Haru ga Kita: Nothing =(
Watashi ga Iu mae ni Dakishimenakya ne: SR Uemura (3x), Sakura One Piece (3x), Sakura High Heel (4x), Sakura Ornament (2x)
Romance no Tochuu: Sakura Ornament
(Some are 2x cause they came up again in a separate game...maybe higher chance on that specific song? Probably all just random for all songs though...I feel like the live drop/reward system for the event replaces what would've been an R card with one of the event clothes/SR Uemura, that's why in the ENTIRETY of this event, I've only seen like 1-2 R drops and that it was relatively easier to get everything...I'm gonna build a 2nd Uemura just cause I picked up a 7th one and there's no Sayuki R+ accessible for me yet)
Edit: Updated 3/19/2015 9:19 EST
I played Watashi Dakishimenakya ne like maybe a dozen times today and got more stuff from that song (I got an Uemura and the whole Sakura costume today just by replaying that song
, and it's never been a bad song to have drops before, sometimes it drops both Uemura and an outfit so I thought it'd be a good song for today and it was =] )
Ren'ai Revolution 21 also seems like a decent song. Sometimes I swap into it and it immediately gives me something during the first three plays. Though, Yume Miru 15 did give me a ton (of the same thing) and it gave me 3 Uemuras despite playing it less than the other 2 songs I mentioned, so i'm about to go for it since I need just Uemuras at this point. I only need 1 more to have a 2nd fully LBed Uemura =) I play too much + not so bad luck = I'm making so much coins (selling extra clothes) + training a good J=J team from this event