Ok I need some advice on how to level up quick so I can beat this DL live. I thought I was doing fine in this game until the DL live came along.

Kiramekirari is Rank 4 while I have Happy! at Rank 9. Miracle Night is at Rank 10 and is scoring around 47,000 (though weird thing is I've lost the rhythm for the song and can now barely play it when I used to be able to do a complete perfect chain on Master). Kiramekirari is scoring around 43,000 at a Chain Complete while Happy! is scoring around 47,100 (with that Chain Boost Z thing you can buy). I'm most likely going to have to use Happy! since leveling up Kiramekirari is going to take too long without magazines, have none left anyway. (All played on Master.)
For the outfit I have the following set:
The outfit you get after the second DL live @ Lv. 2
テイタニアへツドドレス (the flower headset) Rank A Lv. 1
(Sorry don't know the name of the necklace) It's the necklace with the crescent moon on it Rank B Lv. 4
エンプレスブレス (empress bracelet I think) Rank A Lv. 1
Twilight anklet (トワイライトアンクレット) Rank B Lv. 3
My idols are:
Hibiki
4 Hearts
Level 51
Rank A (literally just got her there today)
Burst Rank 15
Omoide Rank 15
Mami
4 Hearts
Level 46
Rank B
Burst Rank 15
Omoide Rank 15
Makoto
4 Hearts Level 46
Rank B
Burst Rank 15
Omoide Rank 15
So what should I do to level them up quickly? (Just going to have to pay for a shitload of lessons to get the Omoide and Burst ranks up if need be. And I suck at the EXP lesson unfortunately.) And is the outfit set I'm using good enough or should I use something different?