Huh, these outdoor events... I wonder if they were free to attend *o* MoMusu at Odaiba, omg... it would be like my dream day.
As far as I'm aware, you just had to buy a copy of "Only You" (at the location in Odaiba) to attend an event. Two copies to go to both. Also, if you arrived to queue up super early and were one of the first 'x amount' to buy a single / get a ticket, you were allowed to stand in a special area which I'm assuming is near the front!
I really wish I could've gone!!!