GODDAMN does anyone have guide for this ?
This is not a formal "guide" but just my advice based on my observations from a few days of play
Spend your first day's money buying 10 of the material in the first town, then the rest of it on mercs there. Then set up your inn with food using that material, a better bed with the feathers you might have gotten on the road, and then explore the roads (leads to next town) and dungeons (multi-level areas for mats) for 10 days. Forget about running the inn and trying to unlock porn for a bit except when the game forces you to do so unless you just want to play around with that for a bit. You'll fail a fair number of check-ins (explained below) and you won't be able to night creep w/o potion recipes so that's why I advise against it but you'll make some money. I've literally never lacked for cash though and I don't even use the cheat so I'd just go farm IMO
Spend all your money on material books (p sure they're for sleeping pill and aphrodisiac recipes), 10 of each buyable material, and then max out on mercenaries in the latest city you've unlocked except the last one, where all you can hire are "bouncers" at varying prices and strength. I find hiring masses of pirates instead of bouncers to be easier, faster, and more efficient because you don't get sent back to the inn (losing a day) when you're done hiring. Explore dungeons for mats, but beware the 10th level of the last labyrinth as it
will cause you to reach the "adventurer" end
If you reach one of the endings, just choose New Game+ (or "enhanced new game" depending on your translation) and you'll keep all recipes, mats, and mercs in your new game but have to unlock all the locations on the map over again
Once you have a lot of mats, you can set up your inn's kitchen (for cooking stat), bar (for "information" stat, though I'm not sure that's being translated and/or presented accurately), and upper floor stuff: the aroma and room decoration (for room stat) to attract porn guests. Those all translate into regular income per day so they're good to keep high, but your goal is to meet the requirements of your porn guests to get them to stay the night. Once they've stayed at least one night you can check their entry in the guest book to see what their NEXT visit's requirements will be and try to meet them. Note: the game has what I consider to be a bug wherein after you "put out the sign" it will go through one day with your current assignments for each category, consuming them, THEN you can choose to "run the inn" or whatever it says in your translation, which leads to a porn guest checking your stats. If you've used up the only ingredient for whatever you assigned somewhere THEY care about (like the last food ingredient for the cooking stat, which happens a lot for me) then when they check in you're at baseline (which will usually be 1) and fail their reqs to stay. Basically save before running the inn in case that happens, then just reload and use another ingredient you have more than one of or go on a week of farming the latest dungeon you've unlocked
After a porn guest HAS checked in, you might get a pure love scene if your stats meet their reqs. I believe they're a separate path than the sexual harassment path and might be cut off if you begin night creeping the guest so beware. I plan to test it more. ANYWAY, once that potential scene is done you'll get the option to either give them a sleeping pill or aphrodisiac - usually alternating, depending on where you're at in their night creeping path. Always choose the strongest you have available (afaict they are, in ascending order of strength, top left, top right, bottom left, then do nothing is bottom right) because the scenes are the same and if the one you use is too weak it'll fail (with no message) and you'll just skip to morning. If it succeeds the game will say so and you'll have the option to enter their room and be treated to some porn. If you don't want to creep them after all you can go to your room (the save room on the first floor) and sleep until morning. Once you've progressed their path enough they'll eventually join the inn as a "maid" and you'll sometimes get more porn scenes with them when you leave the inn and/or after fighting
Anyway, just do that loop over and over until you've unlocked everyone you like and you can revisit their scenes in the gallery. I don't think the DLC characters show up in the gallery though so keep that in mind as you progress the dancer and the tank