I enjoyed this one while reading, enough to go for the LN original as well that has way more content.

It's decently funny but overall I think the worldbuilding is quite good. It's yet another case of "damn my job/life sucks, now something happens to change that", which is a bit overdone in japanese media, but this has a relatively unique setting where he can come and go freely between worlds and has a "master/pet" that teaches him magic and just wants to chill, a master that is very OP.

It turns out, however, that despite their wishes for a peaceful life, various serious events will happen and he'll be dragged into it. He gets pulled into a supernatural psychic department in japan quickly, getting rid of his dead end shit job he had before, he meets various supernatural/fantasy people even on earth and back in the fantasy world he sells stuff from earth, practices magic and helps out a bit, the time difference means he can spend a very long time there without losing out on time in the real world.

What I like the most is that he's fairly realistic for his age. He's not a youngster anymore and doesn't act like one. I wish he could be a bit more energetic, but maybe that'll come with time since the magic and his new lifestyle is clearly influencing his body and mind. He can kill people and doesn't kid himself by trying to be some kind of justice hero. At the same time he's actually pretty damn OP and quickly gets stronger and stronger, but he doesn't let it go to his head, staying true to his goals in life.

The various characters always have a proper role after being introduced and their characters are built gradually, though I'm not too fond of a few of them. Feels like the author goes a bit too much for tragedy/drama at times, like the middle schooler neighbor whose essentially abused by extreme neglect from her mother and has twisted love for the mc who has been giving her food regularly out of sympathy, essentially surviving because of him and then there are other similar characters. I'm not too fond of the idea that a lot of characters should have sob stories as backgrounds, things feel a bit too heavy when that happens. But yeah, it's still an engaging read.

I recommend it. Seems most main cast girls are quite young/lolis though, probably around 12-16 in appearances or age, so keep that in mind. To me that's not a big deal at all, but I know some people hate it. As of now, the mc has no interest in them romantically, although at least one seem to like him in that way (the neighbor).