Chapter 48 (Vigilantes)

A fresh USB of patrol footage brings Koichi to the Hotta brothers' shop in search of Eraser Head, who is away conferring with the police. Jiro floats handing the data to Midnight instead, but Koichi would rather not impose, and Kazuho, the one with any real rapport there, is buried in rehearsals for Captain Celebrity's farewell event.

Down at the station, Naomasa lays out what the Hong Kong client list and the vigilantes' recordings have produced between them: a chain of connections converging on Onomura Pharma Corp. The pharmaceutical firm may be the Villain Factory itself, or at minimum something wired into it. Fat Gum and Monika Kaniyashiki arrive as Shota's assigned partners. Monika has been shadowing the drug trade for a while, while Fat Gum's build makes him the right answer to remodeled villains. The arrangement plants Shota at Monika's shoulder as she works, holds Fat Gum in reserve for actual combat, and sends the trio out to make direct contact with people tied to the company.

The undercover assignments fill the day and hit only minor snags. One of them is Koichi, out patrolling as The Crawler, who spots Monika walking beside Aizawa and cheerfully greets a pair who pretend not to know him.

Back at his penthouse, Koichi tries to share the encounter with Kazuho, but her performance prep leaves her barely listening. Craving any conversation at all, he drifts to the Hotta shop, where the brothers find his company unwelcome now that Eraser Head is not around to irritate them. Shota's name comes up, and Koichi mentions seeing him out with Monika, an idol he recognizes, having no idea she carries a badge. When Shota walks in later, the brothers throw his supposed idol romance in his face out of pure envy, leaving him with no clue what they are talking about.

Naomasa turns up a credible lead on where the Villain Factory operates from. Eraser Head is paired with Fat Gum and Monika for undercover work aimed at the individuals who can point them the rest of the way.

The nineteen page chapter falls in the Sky Egg Arc and reached print on February 23, 2019 before its collection in Volume 7. Ichiro and Jiro Hotta take the cover. Its original serialized title was simply Investigation Time, rendered Sōsa Kaishi, and the longer version arrived with the volume release. Episode 23 of the Vigilantes anime adapts the material.