1 of the concert goods that kept on being sold out since GRANRODEO LIVE TOUR 2017 Pierrot Dancin' started is the umbrella
For future concert dates , each fan can only purchase a maximum of 2 umbrellas per person
http://www.granrodeo.net/news/2017/06/owabi.php
The umbrella is cute but seriously I wouldn't spend 4,000 Yen on it o_O I probably wouldn't dare to use it either