The story takes place in Japan. Kevin and Gwen are out sightseeing while Ben is there to shoot a Mr. Smoothy commercial. Outside the studio a portal forms and out steps the Pack. Ben prepares to fight them when Rex comes out after them. After exchanging greetings, Ben turns into Rath and the fighting begins.
The scene cuts to a flashback in Rex's world. Black Knight has captured The Pack and is willing to help them find Van Kleiss in exchange for them going to a parallel dimension to retrieve a rare element to allow Providence to use time travel. The Pack runs away. Rex uses his hover board and Ben changes to Jetray to chase them but they escape. Rex explains that his brother tipped off Rex to what Black Knight was up to and he followed the Pack through. They found Ben's dimension by tracking the Ultimatrix. Ben's fame gets in the way as he's mobbed by teenage girls. The two switch jackets on purpose so Ben can lose them. They meet up with Kevin and Gwen in a side street and Rex starts hitting on Gwen. Kevin becomes jealous, as Gwen is his girlfriend, so he starts getting ready to pound Rex. Poor Ben is mobbed while Gwen has to separate Kevin and Rex using a mana bubble. Gwen uses her phone to discover there is an atomic particle lab close by. That is likely where the Pack is going.
They are after Promethium, a rare element that is not corrupted by nanites. Rex and Ben's team break in as the Pack is trying to escape through a portal created by I-Bol. Ben goes Spidermonkey and they are stopped from leaving but Biowulf throws what looks like a canister bomb. Gwen shields herself, Ben and Kevin, but the canister explodes all over a lab technician Rex is trying to protect. The technician turns into a mini Godzilla style EVO and crashes out of the building. Rex goes after the technician while Ben and the team go after the pack. With their transporter damaged, they try to flee with Ben going Ultimate Spidermonkey on them. Rex cures the technician and saves downtown Tokyo. He gets mobbed by a group of teenage girls but has to go back to help Ben. The team manages to rescue the Promethium before I-Bol can fix the transporter. The Pack uses the device to flee with hopes to trap Rex in Ben's world but Gwen uses her powers to hold the portal open so Rex can get back. Kevin is more than happy to see Rex leave and laments the idea of there being a next time. It was a good thing Rex never saw Ben wearing the Mr. Smoothy costume. The ad goes viral and Ben is utterly humiliated.
- Ultimate Spidermonkey
- Gwen Tennyson
- Kevin Levin
- Black Knight (flashback only)
- Bobo Haha
- Caesar Salazar (flashback only)
- Rath is the only one of Ben's aliens to appear in the comic and appear in "Heroes United". Jetray and Spidermonkey also appear in a flashback.