From what I can tell from the spoilers, the day before the Onigashima Raid, something happened. The panel we get of Orochi is one, where he’s Onigashima so I think it’s Raid day and the narration says ‘the incident happened the night before’ With that, established I think the panel we get of Momo & Inu is a flash back of the day before. In that panel Momo is asking Inu ‘what are you doing? Won’t you stop at once!’. So I think Inu was left to protect Momo & he’s trying to get away with a boat to save Momo. Momo however wants to stay & fight prolly.
If y’all remember the scabbards were supposed to meet at the port a day earlier than the SHs, so I reckon they were attacked & captured by Orochi. Given Orochi’s chilling & got bitches by his side on the day of the raid lolz