The promotion announced Monday Okuno as Hornbuckle's replacement. According to Chonan, Hornbuckle withdrew from the fight over the weekend due to the flu.
Chonan (18-11), who will be making his Sengoku debut after bouncing around from DEEP, ASTRA and DREAM this year, 3-1 since his UFC exit and recently scored a TKO win over Jun Hee Moon at DEEP 50 in October.
Okuno (10-5-2) is notable for his violent knockout against Nick Thompson at Sengoku 14 in August. At the following event in October, Okuno suffered his first loss in 16 months when he dropped a decision to Yasubey Enomoto.
Below is the complete 28-fight Sengoku "Soul of Fight" lineup with MMA and kickboxing matches. "Jacket rules" are modified MMA rules with each participant wearing the uniform of his respective martial art.
MMA: Marlon Sandro vs. Hatsu Hioki (Sengoku Featherweight Title Fight)
MMA: Kazuo Misaki vs. Mike Seal
Kickboxing: Buakaw Por. Pramuk vs. Hiroki Nakajima
Women's MMA: Megumi Fujii vs. Emi Fujino
MMA: Masanori Kanehara vs. Yoshiro Maeda
MMA: Ryo Chonan vs. Taisuke Okuno
MMA: Maximo Blanco vs. Won Sik Park
MMA: Yasubey Enomoto vs. Keita "K-Taro" Nakamura (SRC Welterweight GP Series 2010 Final)
MMA: Kazunori Yokota vs. Jadamba Narantungalag
MMA: Mamed Khalidov vs. Yuki Sasaki
MMA: Yoshihiro "KISS" Nakao vs. Dave Herman
MMA: Akitoshi Tamura vs. Taiyo Nakahara
Manabu Inoue vs. Shunichi Shimizu (SRC Bantamweight Asia Tournament Semifinals)
Women's MMA: Hitomi Akano vs. Roxanne Modafferi
Women's MMA: Rin Nakai vs. Mika "Hari" Harigai
Women's MMA: Amy Davis vs. Misaki Takimoto
Women's Muay Thai: Erika Kamimura vs. Chiharu
Muay Thai: Fabiano Cyclone vs. Andrew Peck
Kickboxing: Kazuki Osawa vs. Chang Seob Lee
Muay Thai: Norihiro "Musashi" Miyamoto vs. Hiroki Komata
Muay Thai: Kanongsuk Weerasakreck vs. Genki Yamamoto
Muay Thai: Arashi Fujiwara vs. Mutsuki Ebata
Kickboxing: Yutaro Yamauchi vs. Go Yokoyama
Kickboxing: Shintaro Matsukura vs. Yusuke Ikei
Kickboxing: Hironobu Ikegami vs. Yuji Tanaka
"Jacket Rules": Yukio Sakaguchi vs. Jin Suk Jung
"Jacket Rules": Kiyotaka Shimizu vs. Ichiro Sugita
"Jacket Rules": Sotaro Yamada vs. Lee Sak Kim