The mange that I'm looking for is set in modern japan where dungeons have appeared all over the world. The protag is a high school student maybe just out of high school and living with his sister(or step sister, can't remember). He plans to one of nine portals to dungeons that can be accessed in Tokyo. He goes to a shop close to the portals to buy equipment before heading to the dungeon of choice. Before he pays for the equipment a man stops him because it's faulty (i think). After a bit of talking the man tells the protag that he would help the protag level up this day because he finds the protag interesting. In the dungeon the man gives the protag some helpful tips about which levels for which floors and other things. The last thing that happens is that they find a dead women and the man teleports them out of the dungeon and right in to his appartement where an elf is sleeping or just lying on the bed. I think the all happens in the first or first couple of chapters. Later in the series he meets a classmate and makes a party with her and helps her level up, they maybe also fall in love not sure, and even later also a model from the US joins the party. I also remember that they get coins for some kind of gacha mechanics that can be found on the floors of the dungeon, where the can get equipment and other things and the protag has very high luck stat for this.
For some reason i just can't remember the title of the manga.
For some reason i just can't remember the title of the manga.
