Tsutsumi first appears along Suwa inside a room full of monitors observing C-Rankers battling against a common trion soldier. When Kuga defeated the soldier in under a second, he was stunned into silence.
They continued observing, and watched Osamu’s battle against Kazama. When Suwa complained about having to watch their battles when Osamu challenged Kazama one last time, Tsutsumi noted that Osamu had changed and he was looking forward to the upcoming battle. He noted that Kazama managed a shield against Osamu’s attack at the last second, and announced Kazama down.
Tsutsumi appears with the rest of Suwa’s Unit to fight off the newly arrived trion Soldiers. They were among the first to see the new Rabbits. He and Suwa fired, but the Rabbit blocked their shots. When Hisato was shocked into immobility while trying to cut open the Rabbit, Tsutsumi rushed to his side. He was unable to react in time to prevent Suwa turning into a cube.
When Enedra attacked HQ, Tsutsumi appeared alongside Suwa, drawing Enedra away from the fleeing engineers. He managed to avoid Enedra’s cutting attack, which separated him from Suwa and Hisato. When Suwa and Hisato fled into the training room with Enedra chasing, Tsutsumi was the one to activate the battle simulation mode from the outside.
While Suwa and Hisato distracted Enedra, Tsutsumi analyzed Enedra’s trion attacks, and was the one to lock down and identify the trion Shell. It was all for naught when Enedra created multiple shells, and disengaged the training mode by turning into gas.
When Enedra turned into gas to try attacking Shinoda, Tsutsumi turned the AC on, pushing back the gas attack. When Shinoda was unable to move, he and Suwa provided cover and distraction fire for Hisato to get close. He and Suwa provided one last distraction for Kikuchihara and Utagawa to provide the finishing blow.
He, along with the rest of Team Suwa, received an Excellent Service Reward.