The first of three announcements took place today in Korakuen Hall. We know the participants in this year's G1.
Hiroshi Tanahashi
Togi Makabe
Michael Elgin
Kazuchika Okada
Hirooki Goto
Tomohiro Ishii
Toru Yano
YOSHI-HASHI
Kenny Omega
Bad Luck Fale
Tama Tonga
Tetsuya Naito
SANADA
EVIL
Satoshi Kojima
Yuji Nagata
Juice Robinson
Minoru Suzuki
Zack Sabre Jr.
Kota Ibushi
Yuji Nagata has announced this will be his last G1
As has become custom the winner becomes the #1 Contender for the IWGP Heavyweight Championship at Wrestle Kingdom though they have to defend that right in the lead up to that show.