[7] Shiro entered a special schedule high school so that he could spend time training and fighting in Thailand during the year at the 96 Penang Gym.
[9] During the SNKA WINNERS 2016 event, Shiro fought Daniel McGowan for the ISKA World Muay Thai Bantamweight title.
[13] For his second title defense, Shiro was scheduled to fight Gonsalo Tebar at the HOOST CUP Nagoya 4.
[17] Shiro advanced to the semifinals, held on July 21, 2019, where he faced the Rajadamnern Stadium super featherweight champion Rungkit Wor.Sanprapai.
[26] Kido withdrew from the tournament on October 8, as he failed to sufficiently recover from a right orbital floor fracture he sustained in his September 27, 2020, bout with Mutsuki Ebata.
He was replaced by the former SHOOTBOXING Japan super bantamweight champion Seiki Ueyama, who stepped in on a month's notice.
[28] Shiro advanced to the finals, where he faced the reigning RISE Bantamweight champion Masahiko Suzuki.
Aside from winning the money prize, capturing the tournament title earned Shiro the chance to face Tenshin Nasukawa for the second time.
[34] Shiro was booked to face Koudai Hirayama in the quarterfinals of the 2021 RISE Dead or Alive Super Flyweight (-53kg) Tournament, which were held on July 18, 2021.
[3] Shiro faced the KNOCK OUT Super Bantamweight champion Rui Ebata at RISE El Dorado 2022 on April 2, 2022.
[41] Shiro faced the two-time K-1 super bantamweight World Grand Prix runner-up Masashi Kumura at The Match 2022 on June 19, 2022.
They were initially expected to face each other in the semifinals of the 2021 RISE "Dead or Alive" bantamweight tournament, before the fight was cancelled due to Osaki missing weight.
[48] He won the fight by a fifth-round knockout, flooring Diesellek with a head kick at the 2:38 minute mark of the final round.
[51] Shiro advanced to the tournament semifinals, held on August 26, where he faced the one-time Rajadamnern Stadium champion Kumandoi Petchyindee Academy.
[53] Shiro faced Boonlong PetchyindeeAcademy at RISE WORLD SERIES 2023 Final Round on December 16, 2023.
[55] The fight ended in a no-contest, as an accidental clash of heads left Shiro unable to continue competing.