Consensus here appears to be poison, but the "freeze" SFX bubble made me wonder (despite knowing it was Michio's physically pausing) if he'd been hit by any other kind of status ailment. It'd be curious: accelerated heartrate, senses distorted/obstructed with his rapid loss of consciousness...
...given the (rather ominous) "drip" and "squish" sound effects, he's almost certainly been poisoned (like FFVII's--the real deal, not the remake made for those without standards--Bio spells that deliver their effect via damaging green slime), but it was an interesting exercise of the imagination.
This manga had a good start, a low pace but it was well explained and had it reasons, but now it's so fucking boring that literally there's like 30 chapters that you scroll down quickly and it's the same scenario all over
The pedophilic aspect is meant to make up for it; they know lolicons aren't all that discriminating when they have what they're primarily looking for.
Speaking of, it appears Sherry's
logicalitylust was a winner in this comment thread.