Taichi Betsuyaku/Plot

Background
Betsuyaku was scouted by Border from outside the prefecture[BBF Q130] and ended up joining the organization approximately one year before Chika Amatori and Yūma Kuga. Tatsuya Kuruma used to keep an aquarium in the building of Suzunari Branch, but after Betsuyaku accidentally boiled all the tropical fish inside to death no new aquaria were installed.[BBF Q89] On another occasion Kuruma gifted Betsuyaku a hat out of concern for his clumsiness.[BBF Q90]

Around eight months before his unit's match against Nasu Unit and Tamakoma Second, Kō Murakami was found crying in a corner by his teammates. When he heard that Tetsuji Arafune quit being an Attacker, Betsuyaku cheerfully exclaimed that it is because of Murakami's talent, worsening his teammate's mood. Later, however, when he hears the full story through Kuruma's video, he is taken aback by how nice Arafune is.

Introduction Arc
Suzunari First was presumably involved in the extermination of all Rads in Mikado City.

Large-Scale Invasion Arc
Suzunari First is deployed by Masafumi Shinoda to prevent the initial wave of Trion Warriors sent by Aftokrator from reaching Mikado City. Border's traps buy them enough time to arrive on the scene and successfully dispose of the Trion Warriors, but a Rabbit emerges from a carcass. Suzunari First attempts to meet up with Haruaki Azuma, but the Rabbit continues chasing them, until Murakami volunteers to take it on by himself while his teammates meet up with the other B-ranks. Betsuyaku and Kuruma split up and the Sniper goes to Azuma's side. A Gate opens right next to them from which Lamvanein emerges. Azuma orders Betsuyaku to fall back, and the two witness with horror the humanoid Neighbor's power as he single-handedly obliterates Chano Unit. As they run away, however, Lamvanein rapid-fires at them, causing Betsuyaku to bail out.

After the end of the invasion, Suzunari First receives an Excellent Distinguished Service award.

B-Rank Rank Battles Arc
On February 5 Suzunari First fights a rank battle against Nasu Unit, Urushima Unit and Kakizaki Unit, which results in Suzunari First's sixth consecutive victory against Nasu Unit. The following day, Betsuyaku arrives at Suzunari Branch while his teammates discuss Murakami's match against Yūma Kuga. Seeing that Kuruma is going to eat instant noodles, Betsuyaku offers to pour the water for him, which leads to a series of mishaps on his part. Kuruma calms him down and proposes to discuss their strategy for the match against Tamakoma Second after he has eaten.

Two days later, on February 8, after the members of Suzunari First review their plans, they wait for Murakami to wake up. Betsuyaku spawns in the south-eastern area of a shockingly stormy Riverbank, the wind tossing him around in his Bagworm. Despite the downpour he manages to spot Osamu Mikumo and Rei Nasu, and hypothesizes that Chika is wearing Bagworm while Akane Hiura is not. Kuruma instructs him to move towards the river so as to shoot Yūma in case he attempts to cross it with Grasshopper. He proclaims that compared to Lamvanein, Nasu is not a threat.