Eiji Nagasumi/Partners

==List of Digimon==
===Loogamon===
===Tyrannomon===
Eiji Nagasumi also owned four Tyrannomon, though currently only has three of them as one of them was killed by ModokiBetamon.
At some point, Eiji was hired to get a ModokiBetamon for Tomonori Ryusenji.
With Eiji having managed to track one down, he sends three of them to get it, with the three of them chasing it around the subway. Just as they were about to trap their prey in a corner, a subway train drives passed with the Tyrannomon having to get out of the way to avoid being run over. They continue to chase it, with it running into the nearby sewers. As they look for it, one of them is suddenly killed by a surprise attack from it. Eiji, who was eating in local restaurant in the real world whilst they were hunting, received a notification on his Digimon Dock that one of the three Tyrannomon had been killed and — not wanting to fail the mission since he needed the money — quickly replaces the defeated Tyrannomon with the fourth one.
They are eventually able to succeed in catching the ModokiBetamon.
Eiji had been given and a Digimon Linker as a reward for getting Tomonori the ModokiBetamon, and wanting to be able to raise Loogamon properly, he goes onto GriMM and asks for tips on raising dog-like Digimon. He receives a reply, with someone telling him to put his Digimon with other Digimon he owned as they will all play together and learn together. He doesn't bother to read the rest of the reply though, which states that dog Digimon have a social hierarchy and to discipline it first, and instead transfers his three Tyrannomon from his Digimon Dock to his Digimon Linker.
Loogamon, over the next few days, proceeds to make itself leader of the pack. The Tyrannomon fear it, and tremble in fear of the dog Digimon in the corner of their cage during feeding time. As Loogamon was the leader of the pack, it had first dibs on food, and it had even tried to eat one of the Tyrannomon.
When it came time for Eiji to do his mission to be allowed to join the Sons of Chaos as an undercover agent, he chooses not to take the Tyrannomon with him as he was worried they would be too weak for it and as such would die during the mission.
Shortly after Eiji completes the mission in Ninth Avenue, he sends out the three Tyrannomon to collect map data and estimate the population within it. After the Tyrannomon return, Loogamon tells Eiji to have them to continue to patrol the area, so as to make sure no one could invade its territory (as Loogamon had regained some of its memories and remembered Ninth Avenue belonged to it), with Eiji telling them to do just that. A siren blares, causing the Digimon of Ninth Avenue to flee, with Loogamon telling Eiji to recall the Tyrannomon. As Eiji questions it he looks into Loogamon's eyes, realizes it's serious, and does as he's told.
When Eiji comes up with a plan to defeat Leon Alexander's , he decides to trick Leon into going to a floating island of garbage data and has the Tyrannomon hide on it. Unlike in their previous head to head battle, which lost, Loogarmon would use the flames of its Howling Burner to hide and upon putting the flames out with its own attacks is surprised when Loogarmon had just been stood there doing nothing. This shock lasts long enough for Loogarmon to launch a counter attack at Boutmon, and before it can even do anything, is attacked from three separate directions from a sneak attack by the three Tyrannomon. It takes the brunt of the four separate attacks, with Leon confused as to how Boutmon hadn't picked up on them being there. Boutmon states it couldn't due the amount of junk data that was there, and that they had fallen right into Eiji's trap. Boutmon is able to shrug off the flames, as Eiji yells out about how he's going to defeat Leon even if he has to play sneaky to do so. As their attacks clash, Boutmon is able to overpower Loogarmon's flames and get in direct hits against its lower levelled opponent — but is unable to get many of them in as the Tyrannomon's distant attacks are able to distract Boutmon long enough to allow Loogarmon to distance itself. Realizing he wasn't going to win against four opponents who were just trying to wear them down and win in a long drawn out battle Leon decides to have Boutmon digivolve to Kazuchimon. Seeing the Tyrannomon terrified of the Mega level enemy, Eiji recalls them to his Digimon Linker.
When Tomonori Ryusenji betrays the group, he uses a program he had installed into years before to mind control it, and has it fight Eiji's as .
As Soloogarmon avoided Dorugoramon's attacks, they notice Dorugoramon had suddenly stopped paying attention to them and realize it was now aiming its attack at and the others. Eiji was confused, since killing Ryudamon would make accessing the Source Digimon impossible, and realizes his actual target was . He was going to use Pulsemon as a hostage to get what he wanted. Not wanting his friend to die, Soloogarmon changes from aerial attacks to a direct attack but is easily defeated by Dorugoramon at close range. Tomonori tells Eiji he is lucky that he can't kill Soloogarmon, since he still needed it, and mocks the death of Eiji's parents. This further angers Eiji, with Tomonori telling him he had won since no matter what he did he still had Pulsemon. 
Tomonori motions to Pulsemon but reacts in shock when he sees that it, BlackAgumon, and Ryudamon were no longer there. One of Eiji's Tyrannomon arrives, with Tomonori realizing he had had his Tyrannomon do stuff whilst Tomonori was distracted with Soloogarmon. As Tomonori wonders where they had gone, he figures there was only one place they could be — the altar. Eiji and Soloogarmon try to tell the Tyrannomon to flee but they're too late, with Dorugoramon getting there within seconds. Dorugoramon attacks the Tyrannomon at the altar, though Soloogarmon is able to get there in time and block the attack — saving its allies. Tomonori becomes confused, since Eiji could easily replace the Tyrannomon, but Soloogarmon tells him to leave its friends out of their battle. Now even more determined to win, Eiji and Soloogarmon's hearts become even more linked — and with an even higher desire to save their friends — Soloogarmon digivolves to .
Two of Eiji's Tyrannomon take the Mindlinked Shuu Yulin/Ryudamon, Pulsemon, and to the nearby stone circles, with the third limping there having taken damage from Dorugoramon's previous attack. The group now safe, Shuu Yulin watches the battle between the two Mega level Digimon from afar. Kosuke Kisakata's hololized hologram had hitched a ride on the back of the injured Tyrannomon. He apologizes to Yulin, then approaches BlackAgumon with the syringe he hadn't been brave enough to use on it, wanting to put an end to the years of his life dedicated to saving his fiancée. Rather than use it though, he ends up just telling "Saya" how her father had taken everything from him. Yulin tries to comfort him, then tells him to watch with her to see what Eiji and Fenriloogamon could do. As they watch the battle between the two Mega level Digimon, Yulin and Kosuke praise Eiji for all he had achieved despite the many setbacks in his life — as well as how strong his resolve was to save his friends. Figuring he still had one more thing left to do, Kosuke uses the syringe on Pulsemon who proceeds to wake up and join the battle.
The three Tyrannomon then watch the battle from afar alongside the others. 
Around a year after later, Eiji invites his human friends to a birthday party in a yakitori restaurant. Their partners go to the Wall Slums and sit waiting for their partners. Bored, Loogamon brings out food and home made Loogamon branded alcohol — starting a party of its own. They, alongside the other Wall Slum Digimon, watch as Eiji's three Tyrannomon dance. Pulsemon asks Loogamon if it had regained its memories, since it regained some every time it digivolved, though Loogamon simply says "maybe" instead of actually answering. It tells it that it was the past, it would rather focus on the future, and that it wanted to help Eiji have a good life. Pulsemon was amazed by this answer, and the two go back to drinking. After a little more alcohol, Pulsemon asks if Loogamon had invited Kosuke — and as Loogamon tells it that Eiji had invited him it is surprised when a Mindlinked shows up. It, Kosuke, and BlackAgumon had now shown up to the Digimon's party — with Kosuke asking where Eiji was. Loogamon tells him he was on his way, and as they wait — they do a toast. As they toast, Eiji and the others arrive.
Attacks
*Fire Breath: Breathes out intense flames and burns the enemy.