Splatoon (1 and 2) and Luigi's Mansion 3 crossover Agent 4, aka Luna, receives an invitation to a great hotel for a party. She's allowed to bring 5 other people along. She invites Callie, Marie, Agent 3 (Kat), Agent 8 (Amy), and Ruby, her octoling friend. Around the same time, another person receives the same invitation. Upon arriving at the hotel, Luna has taken one step towards an exciting and terrifying night.