On the one hand, we know she's going to survive because she's a main character (and makes up 2/3 of the title), but this fluff is physically painful after that cliffhanger.
@BOTMAN nobody knows what is actually at the bottom of the hole and if they've been throwing enough trash, depending on what sort of things make the bulk, the bottom could be relatively soft... Getting out on the other hand...
Dude can prepare cup noodles? He should have applied for Iron Chef back in his original world.
@Vincentius Do we? I feel like the MC is lacking motivation, desperation, meticulousness, and drive as a somewhat non-OP (so far) isekai protagonist. You could argue that it was partially his careless attitude that led to Professor Lourié's apparent demise. While just fearing she's dead should change his attitude somewhat, the impact would be far more lasting if he found her lifeless corpse. But yeah, I fear it's as you said.