I noticed a reduction in the droprate for rare items in my case pachinco 10x
most of the time I was getting two or more rare boosters, from pachinco 10x
today I think I did not get any.
About droprate of the girls can not say anything because I played yesterday and today
most everything in the arena to climb the Lv up fast to character
Update
Maybe combo Endurance+luck High, with Judges position Helps. Not confirmed yet but there where times
getting money bonus at battle Arena. And is very rare get money bonus at Battle Arena.
in this battle the 3 factors are there