Hyo Sik Hwang. Ogasawara was set to fight Franck Gross for the ISKA K-1 rules World Bantamweight title. Ogasawara won the fight by a unanimous decision. After a draw with Ryo Takahashi, Ogasawara fought Dawsakon Mor.Tassanai for the WPMF World Super Bantamweight title. He won the fight by a third round KO. KNOCK OUT Super Bantamweight tournament He suffered his fourth professional loss to Rui Ebata during KNOCK OUT SURVIVAL DAYS. Ebata won their fight by KO. Eisaku fought in the Rajadamnern Stadium for the first time in August 2018, when he faced Jomkitti Sitanothai. He beat Jomkitti by a second round KO. He was then scheduled to fight King Kyosuke during Rebels 58, and won by unanimous decision. He rematched Ryo Takahashi during KING OF KNOCK OUT 2018, and won by unanimous decision. Eisaku beat Petyaso Dabrunsarakarm by a head kick KO at the Pancrase REBELS Ring 1. Eisaku extended his winning streak to five, with a decision win over Seiki Ueyama. He lost to Yuki Kasahara by TKO, after the ringside doctor stopped the fight in the second round. Ogasawara entered the 2019 KNOCK OUT Super Bantamweight tournament. He won a unanimous decision against Mikel Fernandez in the semifinals, but lost a decision in turn in the finals, in a rematch with Rui Ebata. Rebels 55.5 kg tournament After his loss in the tournament finals, Ogasawara was scheduled to fight Saoek Sitchefboontham. Saoek won by a second round head kick KO. He won his next three fights, defeating Dekdoi TNmuaythai and Issei Saenchaigym by KO, and defeating Kaopong Por.Petchmanee by decision. Ogasawara participated in the Rebels 55.5 kg tournament, facing Keisuke Miyamoto in the tournament semifinals. He won by majority decision. He is scheduled to face his brother Yukinori Ogasawara in the final for the inaugural REBELS-RED 55.5kg title. He was re-scheduled to fight King Kyosuke for the KNOCK OUT RED Super Bantamweight title. He won the fight with a body kick knockout, mid-way through the third round. KNOCK OUT RED Super Bantamweight champion Ogasawara was scheduled to face the former DEEP KICK 57.5kg champion Hiro Yokono in a non-title bout at KNOCK OUT 2021 vol.3 on July 18, 2021. He won the fight by a second-round knockout. Both the knockout and the knockdown that preceded it were scored it the same manner, by low kick, which Ogasawara had been throwing throughout the bout. Ogasawara was scheduled to