NieR:Automata 9S Part 22 gameplay + Quests - YouTube
Side-Quests - NieR Automata Wiki Guide - IGN
NieR: Automata Part #144 - Episode CXXXVIII: 3C3C1D119440927
I'm currently going through and completing the side quests I missed my first playthroughs and cannot find this 9S sidequest. It goes throughout all of chapter 4. : r/nier