Skip the hype for giant monster fights, because this is 100% a comedy filler episode. It’s basically a hilarious anime sitcom where Reno and Iharu try to secret-agent spy on Vice-Captain Hoshina during their day off because they think he's up to something sketchy. Hoshina catches on immediately and spends the rest of the day acting ridiculously suspicious just to completely troll them. If you ask me, it’s a fun, totally skippable detour that just lets you see the crew being goofy and relaxed for once.