[6] He scored some notable participations in Wrestle-1 (W-1), where on the second night of the Wrestle-1 Tour 2017 Shining Winter from December 3, he competed in a 11-man royal rumble also involving Kaz Hayashi, Seiki Yoshioka and Masayuki Kono.

[8] Sekine made his debut in Big Japan Pro Wrestling (BJW) on April 30, 2009 at a house show hosted in partnership with Kaientai Dojo (K-Dojo) where he teamed up with Taishi Takizawa in a losing effort to Atsushi Ohashi and Yoshihito Sasaki.

[12] His last performance was at the 2020 edition of the event where he teamed up with Ryuji Ito and won the Deathmatch Block with a total score of ten points, towering the teams of Abdullah Kobayashi and Yoshihisa Uto, Masaya Takahashi and Kyu Mogami, Masashi Takeda and Takumi Tsukamoto, Takayuki Ueki and Toshiyuki Sakuda, Yuko Miyamoto and Isami Kodaka, and Minoru Fujita and Kankuro Hoshino.

[13] In the Ikkitousen Deathmatch Survivor, he made his first appearance at 2015 edition starting with March 1, placing himself in the Block A and scoring a total of four points after going against Masashi Takeda, Ryuji Ito, Kankuro Hoshino, Jaki Numazawa and Masaya Takahashi.

[14] His last presence was at the 2019 edition of the event, where in the A Block he scored a total of six points after competing against Isami Kodaka, Abdullah Kobayashi, Jimmy Havoc, Ryuji Ito, Yuko Miyamoto and Yoshihisa Uto.

At Judgement 2016: DDT 19th Anniversary on March 21, Sekine participated in a 12-man battle royal for a first contendesrhip contract for the KO-D Openweight Championship also involving the winner Kazuki Hirata, Gorgeous Matsuno, Ken Ohka, Toru Owashi and others.