I haven't figured out where they are either but two of them are popular cheat codes.
The 2nd is reminiscent of a code used in a lot of Sega games, primarily Sonic.
The 3rd is the Konami Code, just with the A at the end replaced with O.
So just a guess, there may be a means (NPC or otherwise) to input those cheats and unlock gallery, etc.
Or maybe it's just gibberish pop-culture references. If anyone finds out before I do, I'm interested to know.
(Side note: as a new member do the forums require us to self-censor names to companies to avoid search flagging?)
Question first: Does anybody know how to trigger all brothel scenes? I ended up with the meat toilet scene (it's like the stuck-in-the-wall scene) and now the owner throws Tsubaki out everytime. There is still an orb in the gallery in the same row as the other brothel scenes and it's name is translated to something like "Kunoichi bought with money". I have no idea what to do about it.
Also with the kunai, if you go south of the hideout there's what looks to be a bubbling spot of water on by the coast. However all I've seen happen is it knocks you down and you lose the kunai as it falls into the water. Not sure if there's some Link to the Past - Wishing Well-esque mechanic to it later.
In Chapter 5 (After the red demon has been beaten) you should find the blue-haired girl in the amusement district. Eventually she will tell you about the water god in the shrine south of the hideout and how he might restore things dropped into the pool. It's possible that you need to trigger this hint, but I wouldn't know what may be required, Go to the shrine; above the bell and the little pier should be another set of bubbles. You might need to ring the bell; I ringed it way before and I didn't have to after I talked to Aoi. You get three options: The first two I haven't tried. Apparently they're about accepting a silver or a gold kunai. The bottom option is translated to "don't care about h-scene"; it will trigger an (rather good) h-scene with the slime and Tsubaki acquires the water god kunai afterwards. It's good, but certainly not the strongest kunai.
Regarding the old man with his arrow/cheat code message: You can later talk to him when he's cowered in the corner; just walk behind that divider. It may look that you can't, but you can. He's the harassment guy we might have met in dungeon 1. No idea what's up with the code.
The brothel cat scene can only be activcated after you watched both in-dungeon cat scenes: I missed the scene in dungeon 2 and turned every stone to find the missing scene (the owner gives you vague hints regarding which conditions might be fulfilled).
May or may not be much help, but while on NG+ and in Chapter 5 I found out what was going on with Yuzu. Not sure on all conditions for it, but I didn't knock out the guy in Chapter 1.
Walked into the bottom right house in the village and had a scene where she was being sold off as a prostitute. In the brothel you can pay 50k and the second scene will occur. I did do all the brothel scenes which may or may not have counted, not sure from dialogue.
Strangely haven't been able to re-buy or find the wine / key item in NG+, though.
I just got this game from DLSite today, and it is fixed in my version.
For anyone who hasn't figured it out, the sparkles on the ground in the 3rd dungeon, requires you to have the Monkey-Jump'n Kunai equipped and THEN jump the gap.
I'm pretty sure the Kunoichi Bought and Sold is from following the directions in the Brothel for a High Class whore. I don't know exactly what this means, but I'm pretty sure you can get it from doing ONLY the brothel scenes, and their prerequisites.