A little clarification:
Everyone in this section must do the OKKUSENMAN shouting.
Agent Yoru o IkuDewgong starts at the beginning, Larto and Derreku come in after the TOKASHITSUKUSHITE TOKASHITSUKUSHITE TOKASHITSUKUSHITE.
Dewgong(Main), Larto, Derekku
Help Me, Erinnnnnn!!Starrodkirby sings the actual song, Takuma, Tode and Larto do the ERIN ERIN and TASUKETE ERIN! bits.
Starrodkirby, Takuma(Backup), Tode(Backup), Larto(Backup)
OkkusenmanThe girls do the first verse (with the URUTORAMAN SEBUN bits), Pas and Derreku do the next bit, then Pas and Miku do MISUGO SHITE TA KESHIKI WA onwards.
[Tode, Dewgong, Lilyko, Miku], [Pasonia, Derekku], [Pasonia, Miku]
Everyone in this section must do the OKKUSENMAN shouting.
SakuraIn this part, everyone basically announces who they are (if you want you can add a little weeaboo touch with "[name] desu") and says basically whatever they want (for example, I suggested rape). I encourage you so say shit like "good work", "nice one" and other general friendly stuff, but don't take too much time. Vyt's gotta cram it all into the space of that song.
Everyone (Speaking, outro), Miku (singing)