After a long wait hearing the name of Mitsukuni Shizuma, Tsuburaya Productions had revealed that the actor Shin Takuma will be playing the said role. The President of Sizuma Foundation and the Founder of TPU, GUTS-Select. He is also the father of Ultraman Trigger's Heroine - Yuna Shizuma.
As per Tsuburaya,
After building the world’s leading business conglomerate, he leveraged his fortune for the greater good of society and created the Sizuma Foundation. In the Foundation’s pursuit of space exploration and ancient alien research, he uncovers a looming, interstellar threat to mankind. In order to confront this menace, he united the governments of the world and established the TPU and the Expert Team GUTS-Select. But deep within his past hides an important secret…
Comment from Shin Takuma
I remember 55 years ago, as a 10-year-old boy, watching Ultraman on TV for the first time and being so excited. And now 55 years later, here I am at age 65, thrilled beyond belief to take on a role in Ultraman. The nostalgia mixed with the realization that I’ve reached this age combined to make this acting experience so much fun. Working on set with the younger members of the team, I just knew that Ultraman Trigger was going to be an amazing Ultraman series. I hope everyone enjoys the show every week.
Additionally, with only a month left from Ultraman Trigger: NEW GENERATION TIGA's broadcast, next week on June 10th, 5 PM (JST), a Livestream Event will feature all the cast members and the director - Koichi Sakamoto. The Livestream will be on TSUBURAYA IMAGINATION. So only the members with a subscription can watch it.
YouTube Livestream hasn't been announced. But hope they have it too.