Tetchō Suehiro/Synopsis

Hunting Dogs Arc
Tetchō arrives together with his fellow Hunting Dogs as summoned by the government to track down the Armed Detective Agency, who have been identified as the Decay of the Angel. As his capsule lands and opens in front of the military police, Tetchō reveals himself posing, while Jōno coldly asks him to go away. He and the latter then help Teruko Ōkura's release from her capsule out of anxiousness for their vice commander.

With the four Hunting Dogs assembled, they discuss the possible routes that the Agency might take to escape from them. They theorize two choices: a southern highway, where the Agency could hijack a getaway car; or the northern train station, where they could blend in among the passengers. In the end, Teruko instructs them to split into two teams, where Tetchō and Jōno take the southern road, while Fukuchi and Teruko take the northern station. With their superhuman speed, the two teams head out.

Tetchō slashes through the trees along their way and eventually reaches their destination. As Jōno voices his dislike for him, he humors Tetchō to stop breathing and his heartbeat given Jōno's keen listening senses, compelling Tetchō to hold his breath in. Jōno then detects the Agency near their spot, to which Tetchō prepares for their encounter. Eventually, Jōno infiltrates their vehicle, pulling out Kenji Miyazawa and Jun'ichirō Tanizaki from inside. Tetchō then prepares his attack on the two detectives, until Doppo Kunikida rams the vehicle into Tetchō to retrieve his comrades. In the Agency's attempt to escape from the Hunting Dogs, Tetchō activates Plum Blossoms in Snow and severs their vehicle into two with his sword.

With the Agency injured, Jōno asks Tetchō to kill Akiko Yosano, whom he calls as the "Angel of Death". As he prepares to kill the doctor, Tetchō is hit by an undetected attack from above. To their shock, Chūya Nakahara arrives and attacks the Hunting Dogs from a chopper with his ability to rescue the Agency.

Despite their high altitude, the Hunting Dogs continue pursuing their targets, with Tetchō using his ability to stab Kenji inside the chopper and hang on the aircraft, noting that nothing shall escape his blade. With the rotors soon to collapse from Tetchō's blade, Kunikida jumps off the chopper and lands on him mid-air. Tetchō notes on his foolishness for thinking they can escape with his action, but Kunikida corrects him and asserts how his ideals shall never falter, detonating a hand grenade on Tetchō and himself.

After Kunikida is hospitalized and put on watch, Tetchō and his fellow Hunting Dogs are requested for dispatch having found the Agency, with Michizō Tachihara rejoining them as the undercover fifth Hunting Dog and cornering Yosano that leads to her arrest.

Sky Casino Arc
As Tachihara returns to the Hunting Dogs' headquarters, he spots Tetchō nearby, having observed an ant colony for eight hours. During their meeting, Tachihara reports that the Agency has been last sighted two days ago at the bank, after which eyewitness reports have stopped coming. As Tetchō is reprimanded by Jōno for muscle training during the meeting, Teruko thinks that the criminals are still within the country and may have conveniently found a base and a leader. To investigate, Tetchō and Jōno head to Café Uzumaki.

They bicker with each other over the title of the "strongest Hunting Dog"; Jōno thinks that such title should belong to someone with impressive investigation and capturing skills, unlike Tetchō's physical strength that earned him such feat. Jōno then challenges him that whichever of them can find the Agency first shall grab hold of the title. Jōno begins questioning the café manager about their waitress Lucy, whom the manager dismisses as a negligible employee, possibly quite insignificant to their investigation on the wanted Agency fugitives. Jōno then lauds the manager's coffee and holds him in admiration, though Jōno confesses that he can see through his lie.

As the manager becomes evidently suspicious, Tetchō stabs Jōno's foot for tormenting the manager during interrogation. Tetchō then takes over the questioning, promising him not to charge Lucy with a single crime if he were to confess her location. Aside from her safety, the manager quips that he also wishes the Agency to be saved, so Tetchō vows on his sword that they shall receive a fair trial. The manager then implores them to save Lucy and reveals to them that she has headed to the Sky Casino.

Kamui Revelation Arc
Two weeks after Fukuchi's return from Standard Island aboard the Boswellian, Tachihara reports to his fellow Hunting Dogs about the bizarre infection-like incident within the Mafia, specifically with an inhuman Ichiyō Higuchi turning Gin Akutagawa and Ryūrō Hirotsu into her kind, as well as witnessing an undead horde of mafiosi. Though Teruko insults how idiotic he reacted, she believes his story, as it coincides with recent disappearances of various mafiosi. Jōno conjectures it might be terrorism using an ability, which Tetchō thinks is the Agency's next terrorist act. Jōno notices Tetchō's seriousness, which he jests will earn a mark on his calendar.

Tachihara subtly implies that the Agency cannot possibly be terrorists after recalling how the detectives kept on mentioning being falsely accused numerous times. Hence, he requests them to allow him to reinvestigate the case. Jōno turns to their commander for his approval.

Vampire Infection Outbreak Arc
Fukuchi rejects the approval of Tachihara investigation the case, claiming that Tachihara's ability is needed in addressing the infection case. Nevertheless, after Tachihara opens his alternative plan using the flash drive he previously broke at the Sky Casino, Fukuchi reluctantly allows him to investigate. Jōno reminds Fukuchi that the flash drive may be another fake planted by the Agency, but Tetchō remarks that Fukuchi nonetheless believes in the possibility that the Agency may not truly be terrorists as he previously said to the UN delegates.

Later at an airport, Tetchō gathers with Teruko and Jōno, and they review their operation: One Order shall be brought to the airport, while 18 fake transport operations are to be deployed, with their commander having claimed that Ranpo Edogawa shall see through the counterfeits and deduce the real weapon. Seeing it as quite bothersome, Jōno recommends taking someone close to the Agency as a hostage to threaten them with, such as the eavesdropping Aya Koda near them. As Jōno threatens and frightens her, Tetchō stabs him with his stretched sword and stops him from further antagonizing her. Jōno asks Tetchō not to stab him every single time and challenges him to a swordfight, but Fukuchi arrives and stops them, afterwards issuing his final preparation orders before the operation.

After an explosion occurred in the airport, Tetchō with Teruko arrive on a vehicle just before the descending plane crashes to the ground. Tetchō activates his ability and tears down the plane resulting to Fukuchi successfully obtaining the One Order. Tetchō and Teruko then regroup with Fukuchi. Later, Tetchō and Teruko head inside the airport, with Tetchō confronting Kenji, Aya, and Bram Stoker.

As Aya and Bram escape per Kenji's instructions, Tetchō questions the detective where they have taken Jōno. Kenji expresses his confusion and instead suggests to look for him together, which Tetchō happily accepts. It soon dawns upon the Hunting Dog that Jōno being taken before by a vampire implies that the Agency is behind his disappearance, immediately striking Kenji with his elongated sword. Kenji manages to catch his blade and flings it, together with Tetchō, up in the air. Forcing Tetchō to unhand his sword, the two engage in a physical deadlock; Tetchō commends the Agency's strength ability, but he avows himself as a Hunting Dog and gets the upper hand, blasting Kenji off the wall.

Tetchō soon lands consecutive strikes on Kenji, finally landing a heavy blow on the detective. He then issues him a last chance to tell him where Jōno is but is soon contacted by Teruko. Learning that she has caught and plans to torture intel out of Atsushi, Tetchō declares that Kenji won't be able to save his friend. With these words, Kenji menacingly kicks off Tetchō off the wall, leaving the latter wonder about the gravity of the boy's ability.

He manages to evade Kenji's truck-splitting punch and attempts to attack him, only to be caught and eventually receive a fatal blow. Admitting his failures towards Jōno and justice, as well as mistaking his enemy, Tetchō rues that he should have chased justice and calmly thought things over. Hence, he asks Kenji to kill him off, but Kenji spares his life and offers to help look for Jōno once more. In the end, Tetchō and Kenji wearily introduce themselves to each other, with the Hunting Dog declaring knowing Kenji's name to be his largest gain for the day. Afterwards, the two end up dozing on the floor.