Does the bag have some special function or are they about to die of carbon dioxide poisoning?

Hat_Vangart said:

Does the bag have some special function or are they about to die of carbon dioxide poisoning?

Unless that Homu-like-girl has some way of switching to have regular air come into her mask, so she can be the "only source of breath" for not-Modoka, they're probably in a murder/suicide arrangement.

Based on the sensory deprivation shown in the samples for the dj, it seems the rebreathing bag is about limiting the air supply, and then being the one supplying the air. Not quite the femdom of simply limiting air supply/breathing. Also, the perverted Homura comparison is rather apt, since the brown haired girl is shown being dressed rather than dressing.

Best guess; Co2 scrubber. It would definitely extend their breathing time, but not by a lot.