So I'm a Spider, So What?, Vol. 6 (manga) - Asahiro Kakashi, Okina Baba, Bianca Pistillo

A mystery man and a smartphone? Things are about to get interesting! I’m continuing to level up and kick some monster booty into the next stratum! But there’s more to this world than I thought…and it seems there are some big figures at play behind the scenes. Like this man, for example—he just popped up out of nowhere! And…what’s this? Holy crap, a cell phone?! Maybe I’ll finally be able to communicate with someone down here in this labyrinth and start getting to the bottom of things!