The Second Japanese Switch Cup (Switch カップ 2 in Japanese) was a tournament in Fortnite: Battle Royale. That was held from February 3rd 2021 to February 6th. By competing in the cup, players will be able to earn the Lovely Outfit, Heartblast Back Bling and the I Sits spray.
The cup will only be accessible on Nintendo Switch, and presumably it will be exclusive to Japan (although you can change your switch region to bypass this).